Tom Schweich  

Discussion - Native Plants

Taxa represented by single collections.

Taxa without infra-specific determinations.

Rare Plants

There are two plants found in Golden s.l. that are ranked as “rare” by the Colorado Natural Heritage Program.

Physaria vitulifera Rydb. “Fiddleleaf Twinpod”

Global Rank: G3, State Rank: S3: Vulnerable, found locally in a restricted range.

Reported as an endemic of central Colorado in the Flora of North America (FNA Vol. 7). Known from Boulder, Clear Creek, Douglas, El Paso, Gilpin, Jefferson, Park and Teller counties.

For a time, it was thought that there was a hybrid, designated Physaria ×1, between P. vitulifera and P. bellii. However, recent phylogenetic work has shown that the putative hybrid fit within the concept of P. vitulifera (Wichmann, 2023).

Spiranthes diluvialis Sheviak. “Ute Ladies' Tresses”

Global Rank: G2G3, State Rank: S2: Widely distributed, but severely threatened where it occurs.

Populations of Ute ladies'-tresses orchids are known from three broad general areas of the interior western United States -- near the base of the eastern slope of the Rocky Mountains in southeastern Wyoming and adjacent Nebraska and north-central and central Colorado; in the upper Colorado River basin, particularly in the Uinta Basin; and in the Bonneville Basin along the Wasatch Front and westward in the eastern Great Basin, in north-central and western Utah, extreme eastern Nevada, and southeastern Idaho.

The species is threatened throughout its range by many forms of water developments, intense domestic livestock grazing, haying, exotic species invasion, fragmentation and urbanization in particular.

In Golden s.l., we do not identify locations where this plant has been found.

Notable Native Plants

Every native plant is notable to a native plant enthusiast. It is hard to pick out just a few for special mention.

Equisetum hyemale L. ssp. affine “Tall Scouring Rush”

There is one published observation (Zeise, 1976) of Equisetum hyemale L. ssp. affine “Tall Scouring Rush” on North Table Mountain, but otherwise no collections in Golden s.l. The closest Jefferson County collection, of which there are very few, was made along Clear Creek about 4 miles above Golden. Most Colorado collections are in the montane west of the Front Range.

Our current Flora of Colorado (Ackerfield, 2022) accepts E. hyemale L. ssp. affine (Engelm.) Calder & Roy L. Taylor, as does Flora of North America. Plants of the World (POWO, 2022) states that the name is a synonym without further enlightenment. Their maps of world-wide distribution show no presence of E. hyemale in North America.

Equisetum laevigatum A. Braun “Smooth Horsetail”

There is only one collection of a “Horsetail” in Golden s.l., that of “Smooth Horsetail” — Equisetum laevigatum A. Braun — made by the author in the Colorado School of Mines Survey Field.

Reports or collection of other Horsetails include E. arvense, E. variegatum, and several hybrids. These reports or collections are scattered widely in Jefferson County. Equisetum is found throughout Colorado, though less dense on the eastern plains and in Moffatt County.

Argyrochosma fendleri (Kunze) Windham “Fendler's False Cloak Fern”

I have never seen this fern in the field and there is just one collection made in Golden s.l. that can be georeferenced, not surprisingly by Loraine Yeatts on South Table Mountain. There is a second collection made in 1944, but the location name is “Table-Top Mountain.” The institution (PH) has georeferenced the collection to the west side of North Table Mountain, but I see no reason to pick that location over any other.

Other collections in Jefferson County are mostly in Clear Creek Canyon, or Ralston Creek canyon. Most Colorado state collections are along the Front Range with scattered occurrences in the mountains to the south.

First collected by Augustus Fendler in 1847 in New Mexico, no detail available, it was described by Kunze (1851) at the University of Berlin.

Cheilanthes feei T. Moore “Slender Lipfern”

Only one collection of “Slender Lipfern” — Cheilanthes feei T. Moore — in Golden s.l., that from South Table Mountain. There is only one other collection from Jefferson County, made along Clear Creek about four miles above Golden. There are many other collections scattered around Colorado.

First described as Myriopteris gracilis by Fee (1852) citing habitat on rocks around Hillsboro, in North America.

Selaginella densa Rydb. “Rocky Mountain Spikemoss”

Known only from two published observations on North Table Mountain (Zeise, 1976; Kilburn & White, 1992). There are six Jefferson County collections. Hundreds of Colorado collections, mostly from the montane.

Published by Rydberg (1900) from specimens known from Montana, the name appears to be nom. illeg. because of S. densa R. Sim, Cat. Brit. Ferns 6: 60 (1859). Accepted by Ackerfield (2022) and Flora of North America.

Selaginella underwoodii Hieron “Underwood's Spikemoss”

One collection on South Table Mountain in a stream gulley.

Cystopteris fragilis (L.) Bernh. “Brittle Bladderfern”

There are collections of “Brittle Bladderfern” — Cystopteris fragilis (L.) Bernh. — from North and South Table Mountains. This fern is more common in the foothills of Jefferson County than out on the high plains. Common fern in the mountains of Colorado, with a few collections out on the southeast plains.

The fern was first described by Linnaeus (1753) as Polypodium fragile from habitats described as the cooler hills of Europe. Cystopteris was proposed by Bernhardi in 1805, who placed C. fragilis therein. This was done in German which, I confess, I have not tried to translate. The fern is widely distributed in both the northern and southern hemisphere.

Woodsia oregana D.C. Eaton ssp. cathcartiana (B.L. Rob.) Windham “Rocky Mountain Woodsia”

Woodsia oregana D.C. Eaton ssp. cathcartiana (B.L. Rob.) Windham — “Rocky Mountain Woodsia” — is found on North and South Table Mountains. It is probably also in Apex Park and on Lookout Mountain but, so far, has not been collected there. There are a few collections scattered around Jefferson County. Most collections in Colorado are from the Front Range and higher southern mountains, with a few collections out on the eastern plains, mostly in canyons or crevices.

Azolla mexicana C. Presl “Mexican Mosquito Fern”

There is only one collection near Golden s.l. along CO Highway 58 just west of McIntyre Street. This is also the only collection in Jefferson County. There are only a few collections along waterways east of the Rocky Mountain Front Range.

Described by Presl (1845) from plants known from Mexico.

It is not clear to me that A. mexicana C. Presl is in question. Some authors apply A. mexicana Schltdl. & Cham., which is further placed in synonomy with A. microphylla Kaulf.

Native Cupressaceae “Junipers” in the Golden s.l. Flora

Juniperus communis L. var. depressa Pursh “Common Juniper”

The Common Juniper — Juniperus communis var. depressa — is found around hilly edges of Golden s.l. such as Tin Cup Ridge or the Survey Field at the base of the Rocky Mountain Front Range scarp. It is likely additionally found at higher elevations in the Front Range, but this very common juniper is clearly undercollected, perhaps because it is so common. For example, the author has seen it at Buffalo Creek, but did not collect it.

The species and all the varieties are called the “Common Juniper.” The species name is a Linnean name published 1753 in his Species Plantarum noting that the plant occurs in the northern woods of Europe. Frederick Pursh (1814) proposed the variety name depressa from plant he had seen live in New York and Maine. The varietal name depressa refers to the overall shape of the plant, giving the appearance of being flattened from above.

Coll. No. 1361, Juniperus communis var. depressa

Juniperus scopulorum Sarg. “Rocky Mountain Juniper”

The Rocky Mountain Juniper — Juniperus scopulorum Sargent — is found in all the hilly areas around Golden s.l., from Tin Cup Ridge on the south to Dakota Ridge on the north. The highly visible ‘Lollipop Tree’ on the west rim of North Table Mountain is a Rocky Mountain Juniper.

The taxon was originally treated as J. virginiana L. or the Red Cedar. C. S. Sargent (1897) recognized J. scopulorum as a separate species. The Rocky Mountain Juniper is found as far east of South Dakota and Nebraska, where it is known to hybridize with its eastern relative J. virginiana in zones of contact in the Missouri River basin. To the west, J. scopulorum is known to occur in Oregon, Nevada, and Arizona, though not California. Hybrids of J. scopulorum and J. osteosperma are known from from Walnut Canyon [Arizona?] north into Utah and east to Mesa Verde.

Native Pinaceae “Pines” in the Golden s.l. Flora

Pinus ponderosa Douglas ex Lawson & C. Lawson. “Ponderosa Pine”

Like the Rocky Mountain Juniper, the Ponderosa Pine — Pinus ponderosa Douglas ex Lawson & C. Lawson — is found on all the hilly areas around Golden s.l., except perhaps South Table Mountain. There is one tree on top of North Table Mountain near the radio tower. These single trees are usually treated as somewhat suspicious as having been planted. At other places such as Dakota Ridge, Windy Saddle Park, Tin Cup Ridge, and Apex Park, there are small natural groves.

The Ponderosa Pine was one of several trees that David Douglas (1799-1834) introduced into cultivation in England following his second expedition to the Pacific Northwest. Another of Douglas' introductions was the Douglas Fir (Pseudotsuga menziesii (Mirb.) Franco). The pine species was described from specimens grown in England and grown in botanic or agricultural gardens. The published description was by Peter Lawson and his son (1836) from plants still in pots at his Agricultural Museum in Edinburgh, Scotland. This was supplemented by a larger specimen growing in the Caledonian Horticultural Society's Gardens, Inverleith Row, now part of the Royal Botanic Garden, also in Edinburgh, Scotland. The specific epithet ponderosa refers to the density of the “… timber said to be so ponderous as almost to sink in water …”

Several varieties of P. ponderosa have been described, and those in Colorado are generally known as variety scopulorum Engelmann in S. Watson (Brewer, Watson, and A. Gray, 1880, vol. 2, pg. 126) though the taxonomy of this complex is far from resolved. Some recent evidence suggests that our variety scopulorum might be better treated at the rank of species (Willyard, et al., 2017). At the generic level, a phylogeny of Pinus was published by Gernandt, et al. (2005).

Ponderosa pine on top of North Table Mountain.

Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco. “Douglas Fir”

There is one tree on North Table Mountain and then, of course, many more on Lookout Mountain.

Coll. No. 1502, Pseudotsuga menziesii var. glauca

Native Salicaceae “Willow Family” in the Golden s.l. Flora

The Salicaceae is the willow family of flowering plants. The traditional family (Salicaceae sensu stricto) included the willows, poplar, aspen, and cottonwoods. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly expanded the circumscription of the family to contain 56 genera and about 1220 species, including the Scyphostegiaceae and many of the former Flacourtiaceae.

Salicaceae

Populus L. “Poplar”

Populus angustifolia E. James “Narrowleaf Cottonwood”

Collected on South Table Mountain and observed on North Table Mountain. Common along Clear Creek where it grows with the Plains Cottonwood. Collected in Jefferson County along the base of the Front Range and slightly up in the foothills. Colorado state collections are from the base of the Front Range to the west.

Described by James in diary entry for July 4, 1820, when the Long expedition was encamped on the South Platte River near Brighton. The holotype is at NY.

Populus deltoides Marshall ssp. monilifera (Aiton) Eckenw. “Plains Cottonwood”

Our common “Plains Cottonwood” — Populus deltoides Marshall ssp. monilifera (Aiton) Eckenw. — has been collected on North and South Table Mountains, and at Dakota Ridge, but not down at Clear Creek. It is there, but the lack of collections is probably an artifact of collector's bias. In Jefferson County, most collections are along the base of the foothills, including the intensely collected areas of Rocky Flats and Chatfield Farms, with a very few collections in the foothills, such as Golden Gate Canyon State Park and Platte Canyon. Colorado state collections are divided into east slope and west slope, with subspecies monilifera in the east slope foothills and out on the plains, and subspecies wizlizenii in the valleys of the west slope.

The species was first described by Marshall (1785) as the “White Poplar” or “Cotton Tree of Carolina” from the banks of large rivers in Carolina and Florida. Separately, William Aiton (1789) described P. monilifera from plants native to Canada and introduced to the Kew garden in 1772. Eckenwalter (1977) assembled our current name by referring P. monilifera as a subspecies of P. deltoides

The varietal epithet monilifera refers to the way the fruits are distributed along the rachis like beads on a string.

Salix amygdaloides (Coll. No. 1886) with Cottonwood in southern Survey Fields.

Populus tremuloides Michx. “Quaking Aspen”

There is only a report of Populus tremuloides Michx. “Quaking Aspen” on North Table Mountain; the author has not seen it. Jefferson County collections are well into the Rocky Mountain foothills. Common along streams and in the mountains where it forms large clonal stands, 6,000 - 11,700 ft. Colorado state collections are in the mountains, though it does get out on Palmer Divide in the Black Forest.

Named by Michaux (1803) from locations in Canada and New York (“Noveboraco”) for its resemblance to the European Populus tremula L. also commonly called “aspen.” At least once our tree was referred to P. tremula subsp. tremuloides (Michx.) Á.Löve & D.Löve .

Salix amygdaloides Andersson “Peachleaf Willow”

Several collections or observations in Golden s.l., including North and South Table Mountains, the Survey Field, and Stonebridge HOA. Most Jefferson County collections are on the plains up to the base of the foothills, with just a few in the lower foothills. Most Colorado state collections are along the base of the foothills or out on the plains, with a few in the valleys of the west slope.

Described by Andersson (1858) with habitat at Fort Pierre on the Missouri River (South Dakota), collected by Prince Maximilian of Wied-Neuwied on his 1832-1834 trip to the Great Plains region of the United States. Andersson saw the specimen in a herbarium in Vienna (“Hb. vindob.”).

Salix exigua Nutt. “Coyote Willow”

The Coyote Willow — Salix exigua — can be found along practically every watercourse in Golden s.l. Of course, it is rarely collected because it is so common. There are reports of it on North Table Mountain, and the writer's collection at Ramstetter Reservoir on the northwest side of the mesa. But, otherwise, no one bothers to collect it except, maybe, in the heavily-collected places, such as Rocky Flats.

It is the only willow that is found in every county of Colorado.

The species was descibed by Nuttall (1842) in his extension of Michaux's North American Sylva as being found in the Territory of Oregon without any additional information about collector, location, date, &c. It it also a little curious that Nuttall mentions no willows in either his report of his residency in Oregon (Nuttall, 1840) or in his descriptions of plants collected by William Gambel (Nuttall, 1848).

Pistillate catkin of Coll. No. 1880, Salix exigua	Staminate catkin of Coll. No. 1880, Salix exigua

Salix irrorata Andersson “Dewystem Willow”

One collection on Lookout Mountain more than 100 years ago. Other collections in Jefferson County include Rocky Flats and Chatfield Farms, in addition to locations in the foothills. Colorado state collections are along the Rocky Mountain front range, with a scattering in southwest Colorado.

Described by Andersson (1858) from a collection by Augustus Fendler in New Mexico.

Betula occidentalis Hook. “Water Birch”

There is one collection, by Wm. Huestis in Golden. The author has seen it in the flood plain of Clear Creek just west of US Highway 6. Collections are scattered around Jefferson County, those on the plains associated with either Clear Creek or Bear Creek. Colorado collections are from the Front Range to the west.

Described by Hooker (1837, v. 2, p. 155) from collections by Dr. Scouler at the Straits of De Fuca, near springs on the west side of the Rocky Mountains (Douglas), and on the east side of the Rocky Mountains to Edmonton House (Drummond).

Coll. No. 2644, Betula occidentalis.

Corylus cornuta Marshall “Beaked Hazelnut”

There is one collection of “Beaked Hazelnut” — Corylus cornuta Marshall — in Golden s.l. It was made by E. H. Brunquist as part of the vegetation survey for the Magic Mountain archeological dig. Brunquist found the plant in the shade of a rocky outcrop in Apex Gulch. Several trees have been observed by the author at that approximate location in Apex Gulch, though not in a condition that would justify collecting. So a confirming collection will have to be made in the future. Collections in Jefferson County have been made in watercourses right at the edge of the Front Range, with a couple more in Golden Gate Canyon State Park. Most of the Colorado collections were made at or near the base of the Front Range.

Our tree was first described by Marshall (1785) giving the common names of “Dwarf Filbert” or “Cuckold-nut,” and described as a smaller version of C. americana Marshall, the “American Hazelnut.” Marshal wrote no description of where the trees were found, or who might have discovered them.

Quercus gambelii Nutt. “Gambel Oak”

Gambel Oak — Quercus gambelii — is found mostly in southern Jefferson County and, until recently, not in Golden. However, the writer found it recently in a canyon in Apex Park. It is also found on Dinosaur Ridge just south of Interstate 70 and therefore just south of the Golden city limits. The Gambel oaks on Eagle Ridge Drive near Kinney Run were planted.

The oak is broadly distributed throughout the American Southwest. For example, the writer has also collected it in the Spring Mountains, Clark County, Nevada, about 45 km. northwest of Las Vegas.

The oak was named by Thomas Nuttall (1848) for its first collector William Gambel who at the age of eighteen set off on his own for California and to collect plants and other specimens for Nuttall. The collection was made on the banks of the Rio del Norte, which we now call the Rio Grande River, presumably somewhere near Santa Fe, New Mexico. The Rio Grande does not actually pass through Santa Fe, but passes some 40 km. to the west.

Coll. No. 2391, Quercus gambelii	Coll. No. 2288, Quercus gambelii

Celtis occidentalis L. “Western Hackberry”

There are no collections of Western Hackberry in Golden s.l., and based on the number and locations of collections it is not clear to me that the tree is native to Colorado. The oldest collection in Jefferson County was made in 1918 (Osterhout, 1918-06-22, RM312384). I include the tree among the natives of Golden s.l. because a specimen has been planted at DeLong Park (2022).

Included in Linnaeus (1753), who noted that it lived in Virginia, and referenced Gronovius (1739) Flora Virginica.

Celtis reticulata Torr. “Net-Leaved Hackberry”

Known mostly from hillslopes on North and South Table Mountains, Dakota Ridge, and Apex Park, “Net-Leaved Hackberry” — Celtis reticulata Torr. — is found occasionally in Golden s.l. Most of the Jefferson County collections have been within a few kilometers of Golden, with notably no collections from Rocky Flats or Chatfield Farms. At the state level the collections are scattered around the state wherever there are rocky slopes and canyons at lower elevations.

The tree was described by Torrey (1828) from collections by Edwin James MD, botanist on the Stephen H. Long expedition of 1820.

Celtis reticulata Torr. is often infested by witches'-broom; caused by a combination of eriophyid mites (Acari) and the powdery mildew fungus

Coll. No. 1799, Celtis reticulata

Humulus neomexicanus (A. Nelson & Cockerell) Rydb. New Mexican Hops

There is a certain amount of dissonance within the botanic community about the various species and varieties of Wild Hops (Humulus sp.) and the names to be applied to them. Here, we follow our current Flora of Colorado (Ackerfield, 2022) and accept that we have one native hops in Colorado that is properly named Humulus neomexicanus (A. Nelson & Cockerell) Rydb. with a common name of “New Mexican Hops” To be sure, there is also a non-native, or European, hops (Humulus lupulus) found in gardens and agricultural fields, but that will be discussed with the non-native plants.

The best place to see our native wild hops is along the Welch Ditch, approximately from the Tough Cuss Bridge to the Suspension Bridge. This location is just outside Golden s.l. Wild hops is also found occasionally in odd places, i.e., in a partially filled in mine pit, on the edges of small wetlands, and in the headscarp of an ancient landslide on North Table Mountain. In Jefferson County, our plant has also been found at Rocky Flats, Ranson/Edwards, and Chatfield Farms. It is generally found from the Front Range west in Colorado.

Five different names have been applied to collections of wild hops in Colorado (Humulus americanus Nutt., H. lupulus L., H. lupulus subsp. americanus (Nutt.) Á.Löve & D.Löve, H. lupulus var. lupuloides E. Small, and H. lupulus var. neomexicanus A. Nelson & Cockerell).

Small (1993+) writing in the Flora of North America North of Mexico accepts H. lupulus var. neomexicanus A. Nelson & Cockerell. Colorado authors Weber and Wittmann (2012) also accept H. lupulus var. neomexicanus Nelson & Cockerell. Meanwhile, Ackerfield (2015 & 2022) treats it at the rank of species as H. neomexicanus Rydb. as does Plants of the World (POWO, 2021-2023).

Confounding factors include the introduction of European domestic hops (H. lupulus L.) to support the beer industry. Wild and domestic hops hybridize leading some to question whether there is any pure native wild hops remaining, except perhaps in the most remote locations.

Wild Hops (Humulus sp.) collections and observations in Golden s.l.	Coll. No. 3199, Humulus neomexicanus.	Coll. No. 3201, Humulus neomexicanus.

Parietaria pensylvanica Willd. “Pennsylvania Pellitory”

One collection at the base of cliffs on the north side of South Table Mountain, plus a collection by Marcus E. Jones that may have been in Golden s.l. or maybe not. Several collections in Jefferson County at the base of, or just barely into, the foothills, including a collection in Bull Gulch (Lippincott Ranch) by the author. Colorado state collections are broadly scattered across the state.

Described by Willdenow (1805) from a manuscript by Muhlenberg, from Pennsylvania, though we now know the native range is continental US and most of Canada.

Urtica dioica L. ssp. gracilis (Aiton) Seland. “Stinging Nettle”

Only one observation in Golden s.l. in the Stonebridge HOA. Probably more common than that. Only four collections in Jefferson County, one by the author at Lippincott Ranch. Most Colorado state collections are in the mountains at lower elevations; not out on the plains or in northwest Colorado.

The subspecies was described by Selander (1947) in Svensk Botanisk Tidskrift [Swedish Botanical Journal] that is not available online.

Santalaceae in the Golden s.l. Flora

The native “misteltoes” were recently moved to Santalaceae from Viscaceae.

Arceuthobium vaginatum (Willd.) J. Presl var. cryptopodium (Engelm.) Cronquist “Pineland Dwarf Mistletoe”

One collection from Lookout Mountain. Other collections from the foothills. Found throughout Colorado, wherever ponderosa pines are found.

Described by George Engelmann in Gray (1850) primarily from a collection by Augustus Fendler in Santa Fe, New Mexico.

Comandra umbellata (L.) Nutt. ssp. pallida (A. DC.) Piehl. “Pale Bastard Toadflax”

Pale Bastard Toadflax — Comandra umbellata (L.) Nutt. ssp. pallida — is common in Golden s.l. and frequently collected. The species is found all across the United States and into Canada, while the subspecies found in Colorado, subspecies pallida, is found between Kansas/Nebraska west to Nevada.

In Jefferson County, it has been collected at Rocky Flats, Ranson/Edwards and North and South Table Mountains, though not at Chatfield, which seems a little odd.

Nuttall (1818) first published the name Comandra umbellata, using a Linnaeus name of Thesium umbellatum as a basionym. C. pallida was proposed by DeCandolle (1857) from a collection made in present-day Nez Perce County, Idaho, by missionary Reverend Henry H. Spalding. Piehl (1965) reduced C. pallida to a subspecies of C. umbellata noting that the various subspecies intergrade. There is thus one species of Comandra in North America with three subspecies, and one subspecies in the Balkan region of Europe. Recent phylogenetic work (Der and Nickrent, 2008) supports a Comandra clade within the Santalaceae.

Comandra umbellata has a couple of interesting characters. First, it is parasitic as apparently is much of the Santalaceae, parasitizing other plants from rhizomes. Second, hairs growing from the petals to the back side of the stamens is somewhat unique. They also play a role in forest pathology as alternate hosts of the comandra-pine blister rust. Finally our subspecies, pallida dies back to the ground each year, resprouting each spring from subterranean buds.

Coll. No. 1373, Comandra umbellata subsp. pallida	Coll. No. 1373, Comandra umbellata subsp. pallida

Native Polygonaceae in the Golden s.l. Flora

Eriogonum alatum Torr. “Winged Buckwheat”

Very distinctive and common around Golden s.l. is the Winged Buckwheat — Eriogonum alatum Torr. — that has a unique appearance among the wild buckwheats. It has a rosette of leaves, and a single tall flower stalk with flowers dispersed in a much branched inflorescence. The plant is monocarpic, meaning that it grows for several seasons, then flowers once, dying in the process.

Winged buckwheat is found sparingly in Jefferson County, primarily in drier sites along the Rocky Mountain foothills. More broadly, the winged buckwheat is found throughout the Colorado Plateau and nearby places.

The taxon name was published by John Torrey in 1857, from a collection made along the Zuni River, in Arizona or New Mexico. Torrey notes that the unique plant was seen in the field as early as 1842 by John Frémont and by other early plant explorers, though he makes no explanation for the delay in publishing a name for the plant.

Winged buckwheat is sometimes treated as Pterogonum alatum (Torr.) Gross, e.g., for Colorado in Weber & Wittmann (2012). However, other authors, e.g., Ackerfield (2015) and Reveal in Flora of North America (Reveal, 2005), place the taxon in Eriogonum reducing Pterogonum to the rank of subgroup.

Eriogonum alatum	Voucher of Coll. No. 2390, Eriogonum alatum

Eriogonum arcuatum Greene “Baker's Buckwheat”

Baker's Buckwheat — Eriogonum arcuatum Greene — is one of two similar-appearing caespitose wild buckwheats found in Golden s.l. The other is the Sulphur-Flower Buckwheat — Eriogonum umbellatum — that is discussed below. The two wild buckwheats can be confused for each other if they are not examined carefully. In E. arcuatum the perianth is hairy externally whereas E. umbellatum is glabrous externally, in addition to other differences.

E. arcuatum has been widely collected in Golden s.l., from Mt. Vernon Canyon in the south, on North and South Table Mountains, to Schweich Hill. It probably can also be found in the other open spaces as well.

There are also observations of E. flavum on North Table Mountain, and a collection there by the writer. Yet today we might identify those plants as E. arcuatum. Users of Weber & Wittmann (2012) would have applied E. flavum to them, because those authors treat E. arcuatum as a local race rather than a separate species. Ackerfield's (2015) Flora of Colorado and Reveal's (2005) treatment of Eriogonum in Flora of North America treat E. arcuatum and E. flavum as a distinct species. This leaves the vouchers of E. flavum and the SEINet data base prepared from those vouchers in a confused state, in that some of those carrying the name E. flavum could very well be E. arcuatum.

Coll. No. 1232, Eriogonum flavum var. flavum arcuatum.	Inflorescence of Coll. No. 1401.1, Eriogonum arcuatum	Coll. No. 1695, Eriogonum arcuatum

Eriogonum effusum Nutt. “Spreading Buckwheat”

Eriogonum effusum Nutt. — “Spreading Buckwheat” — is quite different than the other wild buckwheats found in Golden s.l. As a member of subgroup Eucycla, this one is a subshrub rather than low or spreading.

Nuttall (1848) described Eriogonum effusum in his description of plants collected by William Gambel. It is, however, a Nuttall collection made on the “… Platte plains …” and therefore on his 1834 journey across the Rocky Mountains.

E. effusum is the only representative of Eriogonum subgroup Eucycla that is found in Golden s.l.

Voucher of Coll. No. 2431.1, Eriogonum effusum

Eriogonum umbellatum Torrey, Ann. Lyceum Nat. Hist. New York. 2: 241. 1827. “Sulphur-Flower Buckwheat”

Quntessential Jefferson County plant because the type was collected in Jefferson County by Edwin James, M.D. in 1820. The species is native to western North America from California to Colorado to central Canada, where it is abundant and found in many habitats. This is an extremely variable plant and hard to identify because individuals can look very different from one another. Because of its wide range and many habitats, there are a great many varieties. Six varieties are known from Colorado, and forty-one varieties are recognized by the Flora of North America.

Nearly all of the sulphur-flower buckwheats in Golden s.l. will be var. umbellatum. There is another variety, var. ramulosum, that Jim Reveal (2004) described from Mount Vernon Canyon on the southern edge of Golden. The inflorescence is branched and there is an additional whorl of bracts below the branches of the inflorescence. The writer has also found this variety in the north part of Apex Park, about 3½ km. north of Mount Vernon Canyon.

The most common garden cultivar found in most local nurseries is called “Kannah Creek,” originally from Grand Mesa in western Colorado. It is an excellent choice to start low-water gardening in sunny locations.

Habitat of Coll. No. 1445, Eriogonum umbellatum	Coll. No. 1445, Eriogonum umbellatum var. umbellatum

Eriogonum umbellatum Torr. var. ramulosum Reveal “Buffalo Bill's Sulphur Flower”

Jefferson County collections of this variety are limited to Reveal's (2004) type collections and a collection by the author in Apex Park, just slightly to the north. The other Colorado collections are in or near Estes Park [Collections that appear in Denver and near Foxton are georeferencing errors.]

Eriogonum umbellatum Torr. var. umbellatum. “Sulphur-Flower Buckwheat”

Eriogonum umbellatum Torr. var. umbellatum. “Sulphur-Flower Buckwheat” is found in every Golden s.l. open space. Jefferson County collections are distributed in the northern part of the county, primarily in the intensely-collected locations. It is a little surprising that it has not been collected in the southern part of the county. Colorado state collections are mostly from the Front Range to the west.

Polygonum douglasii Greene “Douglas Knotweed”

Collected in Apex Park and on South Table Mountain, and in the author's garden, Polygonum douglasii Greene “Douglas Knotweed” is a common native “weed.” Most collections are in the urban areas of northern Jefferson County, although the author has collected it in the Buffalo Creek Recreation Area. Colorado collections are mostly in the mountain valleys on the east and west slopes, not out on the plains.

Polygonum engelmannii Greene “Engelmann's Knotweed”

There are two collections of Polygonum engelmannii Greene “Engelmann's Knotweed,” one in 1884 at the generic location of Golden, and the other more recently on private land on Lookout Mountain. Other Jefferson County collections were made at Chatfield Farms and Bergen Park. Colorado state collections are made in the mountainous regions, and not out on the plains.

P. engelmanii has been treated as a variety of P. douglasii.

Polygonum ramosissimum Michx. “Bushy Knotweed”

Rumex triangulivalvis (Danser) Rech. f. “Triangular-Valved Dock”

A collection on South Table Mountain and an observation on North Table Mountain. Jefferson County collections are mostly on the plains with just a few collections in the foothills. Colorado state collections are found from the high plains west along roadsides, in meadows and along streams.

The author has collected our plant at Lippincott Ranch and at Mono Lake, California.

Rumex venosus Pursh “Veiny Dock”

One collection on South Table Mountain and an observation by the author on Dakota Ridge. No other collections in Jefferson County. Mostly a plant of the plains, and found occasionally in northwest Colorado.

Descibed by Pursh (1814, v. 2, supplement, p. 733) from a collection by Bradbury in Upper Louisiana.

Chenopodiaceae Ventenat

Our current Flora of Colorado (Ackerfield, 2022 2nd edition) treats all the “chenopods” within Amaranthaceae as does the Angiosperm Phylogeny Group (Stevens, 2001 onwards) and Plants of the World (POWO, 2023). Our older floras treat them as two separate families.

Atriplex canescens (Pursh) Nutt. “Four-wing Saltbush”

One collection on South Table Mountain (Peter Root, 83-12) made just below the cliff forming the edge of the mesa top. The author has also seen it along Alameda Parkway on the west side of Dinosaur Ridge.

Otherwise, around Jefferson County, it has been collected in the heavly collected places, such as Chatfield and Rocky Flats.

In North American, this taxon is found from the 95^th Meridian (east-central Oklahoma and Texas), west to the southern Coast Ranges of California, and from the north near Calgary, Alberta, south to central Mexico.

The name, as Calligonum canescens, was published by Pursh (1814-1816, v. 2., p. 370) from a collection in the Lewis & Clark herbarium that was made at the Big Bend of the Missouri River on September 21, 1804 (Moulton, 1999). Nuttall (1818, p. 197) moved the plant to Atriplex.

Detail of Coll. No. 721, Atriplex canescens var. canescens	Overview of Coll. No. 721, Atriplex canescens var. canescens

Blitum nuttallianum Schult. “Nuttall's Povertyweed”

Found in a landscaped bed in Golden, so it is unclear whether it was a contaminant in seed, or naturalized there. There were previously three collections from Jefferson County, two from Golden Gate Canyon State Park, and one from the Jewell Mountain property of Boulder OSMP. Colorado collections are scattered widely across the state. Native to western North America, southern Canada, and northern Mexico.

First collected by Thomas Nuttall on dry banks of the Missouri River, who thought it was similar to B. chenopodioides, a native of central Asia (Nuttall, 1818). Named as an American species by Schultes (1822).

Coll. No. 2953, Blitum nuttallianum.	Inflorescence of Coll. No. 2953, Blitum nuttallianum.

Chenopodium atrovirens Rydb. “Pinyon Goosefoot”

There is one collection, made at the site of the Magic Mountain acrheological dig. A couple other Jefferson County collections, around the northern part of the county. Many more Colorado collections, from the Front Range to the west.

Chenopodium berlandieri Moq. “Pitseed Goosefoot”

There are three collections of “Pitseed Goosefoot” — Chenopodium berlandieri Moq. — in Golden s.l., two from South Table Mountain and the other from the base of Lookout Mountain. This would be in the Survey Field or Windy Saddle Park. There are a few collections along the Front Range in Jefferson County. Colorado collections are scattered around the state in disturbed places, along creeks, and open spaces.

The species was described by Moquin-Tandon (1840) from a collection by Berlandier in Mexico.

Suckleya suckleyana (Torr.) Rydb. “Poison Suckleya”

I have not seen “Poison Suckleya” — Suckleya suckleyana (Torr.) Rydb. There is one collection made somewhere near Heritage Square by F. Atherton Riedel in 1940. Otherwise, there are a few Jefferson County collections made on the edges of dry or drying lakes. Most Colorado collections are scattered on the eastern plains.

First described as Obione suckleyana Torr. from a collection made by Dr. George Suckley in the Milk River valley. Dr. Suckley was the surgeon and naturalist on the Northern Pacific Railroad Exploration and Survey (Stevens, 1855). The isotype is at GH, and a holotype at NY. Rydberg (1900) is credited with publishing S. suckleyana.

Amaranthaceae Juss.

Amaranthus arenicola I. M. Johnst. “Sandhill Pigweed”

There is one collection of “Sandhill Pigweed” — Amaranthus arenicola I. M. Johnst. — from the Table Mountain Ranch at the northwest corner of North Table Mountain. That is the only collection of the species in Jefferson County, while the species is found on the eastern plains up to the foothills.

Amaranthus blitoides S. Watson “Mat Amaranth”

I have never seen “Mat Amaranth” — Amaranthus blitoides S. Watson — in my travels around Golden s.l. Or … have I … and overlooked a non-descript weed in the dirt. There are only a few collections around Jefferson County of this species that is scattered around Colorado, except for northwest Colorado.

Amaranthus powellii S. Watson “Powell's Pigweed”

There are just two collections of “Powell's Pigweed” — Amaranthus powellii S. Watson — from Golden s.l., and just two more from all of Jefferson County. Colorado collections are concentrated around Denver and Fort Collins (weedy areas?) and otherwise scattered around Colorado except, again, the northwest.

The pigweed was named for Col. John Wesley Powell, who brought seeds from Arizona.

Froelichia gracilis (Hook.) Moq. “Slender Snakecotton”

“Slender Snakecotton” — there is a name for you! The scientific name — Froelichia gracilis (Hook.) Moq. — is not quite so distinctive. Regardless, there are a few collections in Golden s.l., one from the Peabody Museum archeological dig at Heritage Dells, and one from the intersection of Highways 6 and 58. That area, of course, was recently reconstructed with the development of the Basecamp Apartments, and the Gateway to Clear Creek Canyon parking lot. There are a few other collections scattered around the county, and most of the state collections are on the eastern plains and the base of the Front Range.

The type is a Drummond collection from Texas.

Abronia fragrans Nutt. ex Hook. “Snowball Sand Verbena”

One collection (Ehlers, 8393, 1942) from waste places in Golden. Not seen since. The distribution of Abronia fragrans in the metro Denver area supports the presence of this taxon in Golden s.l. and suggests it may be extirpated here.

Widely distributed in Colorado, primarily on the plains, though also found in the valleys of the Colorado, Gunnison, and Dolores Rivers, and the headwaters of the Huerfano River.

The name was published by Hooker (1853) from a description by Nuttall. Nuttall collected the plant on the sand hills of the Lower Platte, though he does not identify the expedition or the year. It is assumed (by me and others) that the collection was made on his trip to Oregon Territory in 1834. Otherwise, the earliest known collection would be on Fremont's expedition to the Rocky Mountains, 1842. A voucher from Fremont's expedition (NY3370444) was in Torrey's Herbarium, so it would seem that Torrey knew the plant and the name but deferred to Nuttall to publish it.

Mirabilis linearis (Pursh) Heimerl “Narrowleaf Four O'Clock”

Mirabilis linearis (Pursh) Heimerl “Narrowleaf Four O'Clock” is common, but not often seen, in every Golden Open Space. It has been seen in every Golden open space, though a sighting is often accidental because the plant can be hard to see. Narrow and dark green leaves and a brown stem seem to disappear into the background. Most Jefferson County collections were made along the Front Range, with a few in the interior foothills. Our plant has been collected throughout Colorado, though with less density in the northwest quarter.

Mirabilis linearis is in the Four O’Clock family (Nyctaginaceae). The family takes its common name from Mirabilis jalapa L., commonly named the Four O’Clock Flower because the fragrant flowers open in the late afternoon or early evening, and exhale a scent reminiscent of the tobacco flower to attract moths for pollination. Gardeners may also be familiar with another member of the Four O’Clock family, Bougainvillea (Bougainvillea spectabilis Willd.) displaying tiny white flowers surrounded by many showy pink bracts. Bracts are specialized modified leaves that surround the flowers. Similarly, our Narrow-Leaved Four O’Clock has small flowers and smaller fruits and are often outshined by large rose-colored bracts.

Like many of Golden’s native plants, Narrowleaf Four O'Clock was first scientifically recognized from plants along the Missouri River in the Louisiana Purchase. Our friends Thomas Nuttall and Frederick Pursh, and the Missouri River, were involved in the early scientific work. Nuttall (1811) collected seeds along the Missouri River and plants grown from his seeds were for sale from Fraser’s Nursery (London) in 1813 under the name of Calymenia angustifolia. Once again Nuttall gave the plant a name without a description, so his name was another “empty name” (nomen nudum). But a sometimes-traveling companion of Nuttall’s, John Bradbury, who was sent to the Missouri River by the Edinburgh (Scotland) Botanic Garden, also collected our plant, taking his collections back to Scotland. Frederick Pursh saw Bradbury’s dried plants and published them as Allionia linearis in his Flora of North America (1814).

Our plant remained a member of Allionia for a number of years. Anton Heimerl (1857 - 1943) was an Austrian botanist who specialized in our plant’s family (Nyctaginaceae – the Four O’Clock Family). In 1901 he completely reorganized the family. Working from a collection in the Geneva (Switzerland) Botanic Garden made by Earle, Heimerl placed our plant in Mirabilis.

Franklin S. Earle was a biologist and horticulturist of the Alabama Agriculture Experiment Station (1895–1900). He and his wife, Ester, collected our plant north of the El Capitan Mountains, Lincoln County, New Mexico in August 1900. Earle’s plant records are very specific that his wife was a co-collector. It is intriguing to me that an Alabama botanist and his wife were botanizing New Mexico in 1900. Were they vacationing?

Mirabilis nyctaginea (Michx.) MacMill. “Heartleaf Four O'Clock”

Mirabilis nyctaginea (Michx.) MacMill. “Heartleaf Four O'Clock” is found occasionally on North and South Table Mountains, in Deadman Gulch / Kinney Run, and on Tin Cup Ridge. Found mostly on the plains of Jefferson County, right up to the base of the foothills. Most Colorado collections are made from the base of the foothills out onto the plains.

First described by Michaux (1803) as Allionia nyctaginea from habitat on the Tennessee River, placed in Mirabilis by MacMillan (1892, p. 217).

Claytonia lanceolata Pursh “Lanceleaf Springbeauty”

There is one collection of Claytonia lanceolata Pursh “Lanceleaf Springbeauty” that may be in Golden s.l. The author has only found C. rosea, see the next, when collecting.

The species was described by Pursh (1814) from a Lewis & Clark collection made in 1806 at the headwaters of the Kooskooski (Clearwater) River.

Claytonia rosea Rydb. “Rocky Mountain Springbeauty”

A very common early spring wildflower in Golden s.l., Claytonia rosea Rydb. “Rocky Mountain Springbeauty” has been found in every open space except Schweich Hill.

Described by Rydberg (1904) as a segregate from C. caroliniana upon examining herbarium specimens.

Found along the Front Range and into the foothills of Jefferson County. Colorado collections are along the Front Range, and then along the south side of the San Juan Mountains.

Coll. No. 1076, Claytonia rosea

Phemeranthus parviflorus (Nutt.) Kiger “Sunbright”

Sunbright — Phemeranthis parviflorus — is a tiny little perennial that I probably walked over many times before noticing it. The highest density I have seen is in basalt gravel on the southwest quadrant of the top of North Table Mountain, in the same place that Eriogonum arcuatum and E. umbellatum grow together in abundance. It has also been collected on top of South Table Mountain.

It was first collected by Thomas Nuttall on the Arkansas River on his 1818-1820 trip there, and published by Torrey and Gray (1838-1843) as Talinum parviflorum. However, recent molecular and morphological evidence show that the New World genus Phemeranthus in phylogenetically distinct from the generally Old World genus Talinum.

Cerastium arvense L. ssp. strictum Gaudin “Field Chickweed”

“Field Chickweed” — Cerastium arvense L. ssp. strictum Gaudin — is a very common early-blooming wildflower, found in all Golden s.l. open spaces. Found mostly right along the Front Range in Jefferson County, with a few collections in the interior of the county, such as one near Deckers.

Both Cerastium arvense and C. strictum were named by Linnaeus (1753), and Gaudin (1828) reduced strictum to a variety.

Cerastium brachypodum (Engelmann ex A. Gray) B. L. Robinson “Short-stalked mouse-ear chickweed”

Known from three collections on South Table Mountain and one observation on North Table Mountain. Other collections in Jefferson County from Rocky Flats and Lippincott Ranch. Most collections in Colorado are in the Fort Collins and the Boulder-Denver areas, with a few other collections scattered around the state.

Eremogone fendleri (A. Gray) Ikonnikov “Fendler's Sandwort”

There are no collections of “Fendler's Sandwort” — Eremogone fendleri (A. Gray) Ikonnikov — in Golden s.l., only a report from North Table Mountain (Zeise, 1976). There is a concentration of Jefferson County collections in the Rocky Flats and Ranson/Edwards areas, and then a few collections in the southern interior of the county, e.g., Buffalo Creek Recreation Area. Common in Colorado, except on the eastern plains, on rocky or sandy soil of open slopes.

Collected by Augustus Fendler west of Las Vegas, New Mexico, and described by Gray (1849).

Paronychia jamesii Torr. & A. Gray “James' Nailwort”

A small, stiff forb, “James' Nailwort” — Paronychia jamesii Torr. & A. Gray — has been collected on the tops of North and South Table Mountains, on thin soils or growing in rock outcrops. There are four species of Paronychia recognized in Colorado (Ackerfield, 2015), but only one (P. jamesii) is known to occur in Jefferson County. Jefferson County collections are mostly along the Front Range, including Rocky Flats, but not Chatfield Farms. Most Colorado collections are similarly along the Front Range with a few collections out on the eastern plains.

The type (NY342575) was collected by Dr. James, June 26, 1820, probably between Ogallala, Keith County, Nebraska, and Julesburg, Sedgwick County, Colorado.

Pseudostellaria jamesiana (Torr.) W. A. Weber & R. L. Hartm. “Tuber Starwort”

There are two collections of Pseudostellaria jamesiana (Torr.) W. A. Weber & R. L. Hartm. “Tuber Starwort” made in Golden s.l. One is quite old (1901) and gives only Golden as the location. The other was made on the Apex Gulch Trail in 1995. There are a couple of other collections, e.g., Marcus E. Jones #272, that may have been made in or near Golden. Jefferson County collections are distributed around the county, though not at Rocky Flats or Chatfield Farms. My collection from Bull Gulch (Lippincott Ranch) is not online yet. Colorado collections are scattered around the state, except for the eastern plains.

Described first from a Dr. Edwin James collection (Torrey, 1827), although James' diary makes no mention of the collection. Weber & Hartman (1979) moved the plant to Pseudostellaria because of its similarity to that Asiatic genus.

Coll. No. 2787, Pseudostellaria jamesiana

Silene antirrhina L. “Sleepy Catchfly”

There are three collections of Silene antirrhina L. “Sleepy Catchfly” in Golden s.l., one by the author in the Survey Field, one from South Table Mountain, and a Marcus E. Jones collection from “foothills near Golden.” Other collections in Jefferson County were made at Rocky Flats, and White Ranch Park. Colorado collections are concentrated along the Front Range and in the valleys of southwestern Colorado.

The species was described by Linnaeus (1753) as being native to Virginia and Carolina. We now know it is found from Canada to Mexico (POWO).

Silene drummondii Hook. “Drummond's Campion”

There is one collection of Silene drummondii Hook. “Drummond's Campion” made in Golden s.l., made by Edward L. Greene in 1872. It is on the same sheet as a Hall & Harbour collection of the same taxon. Other collections in Jefferson County were made at Rocky Flats, with a single collection from the Tarryall Mountains. Colorado collections are from the Front Range to the west, for the most part.

The taxon was described by Hooker (1830) from collections by Richardson, Drummond, and Douglas.

Actaea rubra (Aiton) Willd. “Red Baneberry”

One collection of Actaea rubra (Aiton) Willd. “Red Baneberry” may be in Golden s.l.. It was made in 1916 by William Huestis. Of the other Jefferson County collections, two were made in the Lost Creek Wilderness, one in Golden Gate Canyon State Park, and one by the author at Lippincott Ranch. Colorado state collections are from the Front Range to the west.

Anemone canadensis L. “Canada Anemone”

There are three Anemone collected on Lookout Mountain: A. canadensis, A. cylindrica, and A. multifida. All of the collections were made more than 100 years ago.

Of the three, A. canadensis is most common in Jefferson County. Most of the Colorado state collections were made in the Front Ranges.

Described by Linnaeus (1768) as living in Pennsylvania.

Anemone cylindrica A. Gray “Candle Anemone”

Anemone multifida Poir. var. multifida “Pacific Anemone”

Collections that may be in Golden s.l. are on Lookout Mountain or in foothills near Golden. The other Jefferson County collection is along US I-70 near Beaver Brook. Colorado state collections are in the mountains west of the Front Range. The author has collected our plant in Evans Gulch, Lake County, near Leadville.

Be careful to distinguish between Anemone multifida Poir. var. multifida and Anemone patens L. var. multifida Pritzel.

Aquilegia coerulea E. James “Colorado Blue Columbine”

Two collections, both on Lookout Mountain, and both more than 100 years ago. Most Jefferson County collections are in the foothills of the Front Ranges. Colorado state collections are in the mountains from the Front Range to the west.

Described by Edwin James from a collection he made at Elephant Rock, near Palmer Lake, El Paso County.

Aquilegia saximontana Rydb. “Rocky Mountain Columbine”

One collection on Lookout Mountain well more than 100 years ago. The only collection of our plant made in Jefferson County. Most Colorado state collections are well into the mountains, with a little concentration around Torrey and Gray Peaks.

Clematis columbiana (Nutt.) Torr. & A. Gray “Rock Clematis”

There are three collections on Lookout Mountain that may be within Golden s.l.. I have not seen this; C. ligusticifolia is more common around Golden.

The plant was originally named Atragene columbiana Nutt. from a Nathaniel Wyeth collection on his return from Oregon Territory in 1833. Atragene is a Linnean name that DeCandolle reduced to a section of Clematis in 1818. Weber & Witmann (2012) continue to treat it at the rank of genus. Ackerfield (2015) accepts Clematis columbiana (Nutt.) Torr. & A. Gray, placing Atragene columbiana Nutt. in synonomy.

Coll. No. 2780, Clematis columbiana

Clematis hirsutissima Pursh “Hairy Clematis, Sugar Bowls”

Clematis ligusticifolia Nutt. “Western White Clematis”

Fairly common around Golden s.l. Typically I associate this species with more mesic sites perhaps along the edges of riparian zones. However, I have also collected it in a partially-filled in mining pit on Eagle Ridge.

The name was published by Torrey & A. Gray (1838, v. 1, p. 9) in their Flora of North America from a manuscript by Thomas Nuttall. Nuttall was describing a plant he collected on the Snake River in 1834 on his trip to Oregon Territory.

The third Clematis found in Golden is C. orientalis, a List B noxious weed.

Delphinium carolinianum ssp. virescens (Nutt.) R.E. Brooks “Plains Larkspur”

The Plains Larkspur — Delphinium carolinianum subsp. virescens — is found occasionally throughout Golden s.l. I think it is a little later than Nuttall's Larkspur and, just when it seems there will not be any, the Plains Larkspurs begin to bloom. It has been collected or observed in all the open spaces of Golden. Generally, the Plains Larkspur is found on the plains and just barely into the foothills. There are a few collections west of the Continental Divide. However, these may be outliers or misidentifications.

Of the three larkspurs known from Golden s.l., this is the only one that is usually white. The other two D. geyeri and D. nuttallianum are typically blue.

The Plains Larkspur was first described by Thomas Nuttall (1818), as being on the plains of the Missouri. Presumably, Nuttall also collected it. However, so far I have not found a collection or reference to a type.

Delphinium is very much a global genus and phylogenetic data (Jabbour and Renner, 2012) suggests that it originated in early Oligocene, possibly in the Mediterranean region, and crossed into North America from Asia in the Pliocene.

Coll. No. 2359, Delphinium carolinianum subsp. virescens	Coll. No. 1440, Delphinium carolinianum subsp. virescens

Delphinium geyeri Greene “Geyer's Larkspur”

Just three collections in the south west margin of Golden s.l. and an observation on North Table Mountain. One collection “plains at base of Lookout Mountain” may be in the Survey Field, though the author has not seen it there. Collections in Jefferson County are along the base of the Front Range. Colorado state collections tend to be along the Front Range from Morrison north, and then out on the Pawnee National Grassland.

The name was applied by Greene (1893) who cited collections by Nuttall and Geyer.

Delphinium nuttallianum Pritz. “Twolobe Larkspur”

Myosurus minimus L. “Tiny Mousetail”

Around Golden s.l., this tiny little plant has been found only on top of North Table Mountain, in drying ponds and muddy places. A little more broadly, in Jefferson County, it has been collected numerous times at Rocky Flats. Otherwise widely scattered throughout Colorado except the eastern plains. Native to Colorado, and much of the United States and Europe.

The first mention of Tiny Mousetails in Colorado was in Porter & Coulter (1874, p. 2) who note it was collected by Hall & Harbour in South Park.

Pulsatilla nuttalliana (DC.) Spreng. “Nuttall's Pasque Flower”

For a very common plant, there are very few collections of Pulsatilla nuttalliana (DC.) Spreng. that have been made in Golden s.l.. Actually only one collection is definitely from Golden. Specific searches for our plant in the Survey Field and on Dakota Ridge had found none. Jefferson County collections are scattered around the county, except at the lower elevation locations, such as Chatfield Farms. Most Colorado state collections are found from the Front Range to the west, on open hillsides, meadows, and forests, up to 13,000 ft.

Plants of the World (POWO, 2022) treats our plant as Pulsatilla nuttalliana (DC.) Bercht. & J.Presl., a strictly North American entity. Anemone patens var. multifida, a formerly applied name, is not accepted, and is treated as a synonym of Pulsatilla patens subsp. multifida (Pritz.) Zämelis, with its distribution mapped as eastern European Russia to Kamchatka and northern China.

Ranunculus acriformis A. Gray “Sharpleaf Buttercup”

One collection near Golden s.l. in Mount Vernon Canyon. However, also compare to Loraine Yeatts #4618, which was originally determined R. sceleratus, but one voucher (COLO500167) has been annotated R. acriformis.

Distinguished from R. acris by a longer beak on the achene.

Ranunculus aquatilis L. var. diffusus With. “Threadleaf Crowfoot”

In Golden s.l., Ranunculus aquatilis L. var. diffusus With. “Threadleaf Crowfoot” has been found only in Lake Vaca on top of NorthTable Mountain. Most Jefferson County collections of our plant are from intensely-collected Rocky Flats. Most Colorado state collrctions are in the mountains with just a few out on the plains.

Described by Withering (1796) from plants in England, with little comment or discussion of the plants from elsewhere.

Ranunculus cymbalaria Pursh “Alkali Buttercup”

The only collection of Ranunculus cymbalaria Pursh “Alkali Buttercup” in Golden s.l. was by the author at Lake Vaca on top of North Table Mountain. There are few other collections in Jefferson County, mostly in muddy areas on the plains. Colorado state collections are scattered in the state except in the highest mountains. The author has also collected it in Esmeralda County, Nevada, and Mono County, California.

Our plant was described by Pursh (1814, v. 2, p. 392) from plants he had seen in saline marshes of Onondago, New York.

There is some pretty good evidence (Emadzade, et al., 2010) that Halerpestes cymbalaria (Pursh) Greene better reflects the molecular and morphologic phylogeny of this plant within the Ranunculaceae. Ackerfield (2022) Flora of Colorado and Plants of the World (Kew, 2020) has accepted this, whereas FNANM has not.

Ranunculus glaberrimus Hook. var. ellipticus (Greene) Greene “Sagebrush Buttercup”

Collected in 1872 in "Golden City" by E. L. Greene, and then not again until 2020 when it was collected in Apex Park by the author. Several Jefferson County collections along the edge of the Front Range. Colorado state collections are mostly in the mountains below 10,000 feet.

The species was described by Hooker (1829) from collections by Douglas. The variety was first published at the rank of species (Greene, 1890) citing collections from mountain districts of Colorado, Utah, and Nevada to eastern California. Greene (18920 then reduced our plant to rank of variety under R. glaberrimus citing a type colleced near Truckee, California.

Ranunculus ranunculinus (Nutt.) Rydb. “Tadpole Buttercup”

There is one observation of Ranunculus ranunculinus (Nutt.) Rydb. “Tadpole Buttercup” within Golden s.l., beside an ephemeral stream low on the initial Front Range slope. There are seven collections in northern Jefferson County, made at the base to the lower Front Range. State-wide collections are found along the northern Front Range, and in the Gunnison River basin.

First collected near Independence Rock, Natrona County, Wyoming by Thomas Nuttall (1834) and published Cyrtoryncha ranunculina Nutt. by Torrey & A. Gray (1838-1840) from a Nuttall manuscript. Rydberg (1894) published as Ranunculus ranunculinus without comment.

However, recent molecular and morphology phylogeny (Emadzade, et al., 2010) suggests that Cyrtoryncha forms a well-supported clade with Trautvetteria, Halerpestes, Oxygraphis, Arcteranthis, and Beckwithia, well-separated from Ranunculus s.s. Of these, only Trautvetteria, Halerpestes and Cyrtoryncha are known to occur in Colorado.

Ranunculus sceleratus L. “Cursed Buttercup”

Collected on North and South Table Mountains, in damp soil, or at edges of ponds. Other locations in Jefferson County are damp places on the plains in the northern part of the county. Colorado state collections are widely scattered throughout the state.

Described by Linnaeus (1753) as being found in trenches and marshes of Europe, though today we describe its native range as temperate Eurasia, north Africa, Ethiopia to Rwanda, central & eastern Canada to central & eastern U.S.A.

Berberis repens Lindl. “Creeping Barberry”

“Creeping Barberry” — Berberis repens Lindl. — has been collected or observed in every Golden s.l. open space. There are not very many collections in Jefferson County, and those are mainly right along the Front Range, but I suspect it is far more common than the number of collections would imply. The plant is not found on the plains, but is common from the Front Range west.

According to Lindley (1828), seed was collected by the Lewis & Clark party, from which plants raised in American, then sold, and one growing in the Garden of the Horticultural Society (London) was then described by Lindley.

Argemone hispida A. Gray “Rough Prickly Poppy”

Two collections, one definitely from Golden s.l., and one probably just south in Mount Vernon Canyon. The few collections of this species, are along the base of the Front Range. Colorado collections are also along the Front Range and in the interior valleys.

Described by Gray (1849) from a collection around Santa Fe, also noting collections by Fremont and Wislizenus.

Distinguished from the next primarily on the density of prickles on the stem.

Argemone polyanthemos (Fedde) G.B. Ownbey “Crested Prickly Poppy”

Very pretty and very stickery, “Crested Prickly Poppy” — Argemone polyanthemos (Fedde) G.B. Ownbey — is found in all the open spaces of Golden s.l. This vegetative parts of this very pretty flower are so prickly that it is sometimes mistaken for a thistle or a cactus. It also has an orange latex-bearing sap that is very sticky.

The genus name Argemone is derived from the Greek “argema,” a reference to the use of a European prickly poppy in medicine. The species name is a combination of the Greek words “poly” (meaning “many”) and “anthemom” (meaning “flowers”). The “Crested” part of its common name refers to the horns or crests on the seed pods.

Prickly poppies grown from Mexican seeds were growing in European gardens when Linneaus (1753) published the first edition of his Species Plantarum, but those were a different species than our prickly poppy. The historical literature is a little unclear, but it appears that the first collection of A. polyanthemos was very likely made by Edwin James, MD, on June 20, 1820, just west of Gothenburg, Nebraska. Unfortunately, James gave it a name that was previously used for a different poppy, and our plant received little recognition. It wasn’t until 1958 that Gerald Ownbey of the University of Minnesota reorganized all the prickly poppies and elevated our prickly poppy to the rank of species.

I have placed those collections determined A. intermedia Sweet and A. intermedia auct. non Sweet into A. polyanthemos. A. intermedia is a confused name that cannot be resolved to any species of Argemone with assurance (Ownbey, 1958).

Our plant is found mostly on the plains and lower foothills from Texas north to Montana. In Colorado it is found on the plains and up against the foothills, with a few collections in the southwest part of the state. Although, one must wonder whether the poppy occurs there naturally or whether it is a garden escapee there.

You may notice in the photograph that there is a semi-circular cutout in the petals on the back side of the flower. Colorado’s native leafcutting bees (Megachile spp., see inset) cut leaves and flower petals and use the pieces to line their nest cells. Colorado State University has an interesting article about leafcutting bees at: https://extension.colostate.edu/topic-areas/insects/leafcutter-bees-5-576/

Habitat of Coll. No. 1484, Argemone polyanthemos	Flower of Coll. No. 1484, Argemone polyanthemos	Leaf-cutting bee cutting semi-circular segments from petals of Argemone polyanthemos.

Corydalis aurea Willd. “Scrambled Eggs”

An annual or possibly biennial found occasionally on North and South Table Mountains. Bright yellow flowers.

The plant was first collected in Canada, and taken to the Berlin garden, grown there, and described by Willdenow (1809).

Scattered around Jefferson County, and widely distributed in Colorado in mountains and foothills, with a few found out in the plains, in places such as blow-out sand, or along streams.

Native Mustards (Brassicaceae) in the Golden s.l. Flora

Arabis pycnocarpa M. Hopkins var. pycnocarpa “Cream Flower Rockcress”

The only Arabis remaining in Colorado after the group was split apart, mostly into Boechera, but also Turritis, Arabis pycnocarpa M. Hopkins var. pycnocarpa “Cream Flower Rockcress” has been colleted on North and South Table Mountains and Tin Cup Ridge. Jefferson County collections on the plains have been at some of the higher elevation sites, such as Rocky Flats and Ranson/Edwards, though not at Chatfield Farms, plus a few collections in the interior of the county. State-wide, most Colorado collections were made in the interior forests, meadows, and grasslands.

The name A. pycnocarpa M. Hopkins (1937) was proposed to separate a strictly American plants from the European name of A. hirsuta.

Coll. No. 2935, Arabis pycnocarpa var. pcynocarpa.

Boechera fendleri (S.Watson) W.A.Weber “Fendler's Rockcress”

“Fendler's Rockcress” — Boechera fendleri (S.Watson) W.A.Weber (Syn: Arabis fendleri (S. Watson) Greene ) — has been collected on North and South Table Mountains. It is probably more probably more common than the number of collections would suggest, but is easily overlooked. See the photo at left; there are six plants in bloom between the field press and field notebook.

The author has also seen it at Ranson/Edwards and there are several collections from Rocky Flats. Found in Colorado from the Front Range to the west, and also in Utah, Nevada, Arizona, and New Mexico.

The type was collected by Augustus Fendler (no. 27, 1847) in New Mexico. The holotype is at GH, isotypes at K, MO, UC. Gray did not publish the name in Plantae Fendlerianae Novi-Mexicanae (Gray, 1849), nor did he refer to Fendler coll. no. 27. It was not published until Watson's (1878) revision of Gray's Syntopical Flora of North America.

Descurainia incisa (Engelm.) Britton “ Mountain Tansy Mustard”

“Mountain Tansy Mustard” — Descurainia incisa (Engelm.) Britton “ and the next (D. pinnata) are often mistaken for each other. Consequently, one will find vouchers of the same collection annotated as the other. That being the case, I believe there are two collections of D. incisa in Golden s.l., both from South Table Mountain, plus an additional collection from Clear Creek Canyon, very near to Golden s.l. There is one other Jefferson County collection from Lakewood. It is determined ssp. viscosa, which is now treated as a synonym of ssp. incisa. Colorado-wide, collections of D. incisa are made from the highest plains to the Utah border.

Originally named Sisymbrium incisum Engelm. in Gray's (1849) Plantae Fendlerianae, it was placed in Descurainia by Britton, et al. (1894) as part of a larger effort to standardize nomenclature.

Coll. No. 2464, Descurainia incisa ssp. incisa

Descurainia pinnata (Walter) Britton “Western Tansymustard”

Similar to the previous, Descurainia pinnata (Walter) Britton “Western Tansymustard” is only known in Golden s.l. from a single voucher of a collection on South Table Mountain. Another voucher of this collection has been annotated D. incisa. Other collections from Jefferson County are clustered in the northern part, and most of them are from Rocky Flats. Somewhat more common in Colorado, collections are scattered around the state.

First named Erysimum pinnatum Walter (1788), Nuttall (1818) placed it in Sisymbrium, and finally consolidated as Descurainia pinnata (Walter) Britton (1892).

Draba reptans (Lam.) Fernald “Carolina Whitlow Grass”

Draba reptans (Lam.) Fernald “Carolina Whitlow Grass” has been collected in “Golden,” on South Table Mountain, and at the Magic Mountain Archeological Dig. The writer has collected it twice at Ranson/Edwards but has not seen it in Golden s.l. Further afield in Jefferson County this tiny little annual has been collected at Rocky Flats and Beaver Brook. Generally, it is found early in the botanic season on dry slopes, rocky outcrops, and in grasslands, throughout Colorado, except on the eastern plains and the high mountains.

The common name Whitlow Grass refers to members of the genus being formerly used to treat a viral infection of fingers and toes and comes from the Middle English whitflawe or “white flow.”

First placed in Arabis as A. reptans by Lamarck (1783), it bounced around until Fernald (1934) placed it in Draba.

Coll. No. 1376, Draba reptans

Erysimum asperum (Nutt.) DC. “Prairie Wallflower”

Collected on Lookout Mountain and below Lookout Mountain (probably the Survey Field), with several older collections giving a location of “Golden” Also reported on North Table Mountain.

Collected thoughout Colorado, though more commonly along the northern Front Range and in southeast Colorado. Tends to occur more on prairies, sand dunes, roadsides, bluffs, sandhills along stream banks, knolls, and open plains. through west-central North America.

Less common in Golden s.l. than E. capitatum from which it differs by details of the fruit, or the position in which the fruit is held, but is more commonly found on hillsides, sry slopes, and meadows.

Erysimum capitatum (Hook.) Greene “Sanddune Wallflower”

Found throughout Golden s.l.. though rarely in large numbers. Found mostly along the Front Range in Jefferson County. Similarly, found throughout Colorado, though with just a few collections on the eastern plains.

First described by Douglas and published in Hooker (1829) as Chieranthus capitatus, and later moved to Erysimum capitatum by Greene (1891), who was then writing about the flora of middle California.

Coll. No. 2474, Erysimum capitatum

Noccaea fendleri (A. Gray) Holub ssp. glauca (A. Nelson) Al-Shehbaz & M. Koch “Alpine Pennycress”

Actual collections of Noccaea fendleri (A. Gray) Holub ssp. glauca (A. Nelson) Al-Shehbaz & M. Koch “Alpine Pennycress” are only from Lookout Mountain, and thus may be in Golden s.l., plus there is one observation about mid-slope that is definitely within the limits of this flora. There are several other collections around Jefferson County, including the author's collections at Ranson/Edwards, but no collections from Rocky Flats, and a few more from the interior of the county. Colorado collections are mainly from the Front Range west, up to 14,000 feet, though not in the valley bottoms.

Ours was first recognized by Aven Nelson (1896) in his First Report on the Flora of Wyoming as Thlaspi alpestre var. glaucum then elevated to by rank of species by Nelson (1898) when he had seen more material. It remained in Thlaspi until 1998 when phylogenetic work showed Noccaea to be a distinct species. Subsequent reorganizations placed our plant as a subspecies of Noccaea fendleri.

Physaria montana (A. Gray) Greene “Mountain Bladderpod”

“Mountain Bladderpod” — Physaria montana (A. Gray) Greene — is very common in Golden s.l. and has been found in all the open spaces. Collections in Jefferson County are clustered around Golden s.l., Chatfield Farms, and Rocky Flats, with a few collections in the central county foothills. There are no collections from the interior of southern Jefferson County.

First described as Vesicaria montana A. Gray from a Hall & Harbour collection. Watson (1888) placed the plant in Lesquerella a rather large genus in the Brassicaceae. Greene (1891) placed the plant in Physaria without referring to Watson's Lesquerella, perhaps he did not know of it. Greene's proposal was ignored, e.g., Gray (1895) Syntopical Flora of North America. Al-Shehbaz & O'Kane (2002) moved most Lesquerella to Physaria as indicated by phylogenetic analysis, thus elevating Greene's placement to the accepted name for the taxon.

Some synonyms of Physaria montana, specifically Vesicaria montana and Lesquerella montana, are treated as accepted names in the SEINet taxon tree. Searches for all three names are required to ensure that records for all vouchers are returned.

Physaria vitulifera Rydb. “Fiddleleaf Twinpod”

Physaria vitulifera Rydb. — “Fiddleleaf Twinpod” — is found on slopes and in rocks on North and South Table Mountains and in Kinney Run. Known from Boulder, Clear Creek, Douglas, El Paso, Gilpin, Jefferson, Park and Teller counties, it is endemic to central Colorado, and considered vulnerable because it is found locally in a restricted range. I has a Global Rank: G3, State Rank: S3.:

For a time, it was thought that there was a hybrid, designated Physaria ×1, between P. vitulifera and P. bellii. However, recent phylogenetic work has shown that the putative hybrid fit within the concept of P. vitulifera (Wichmann, 2023).

Rorippa palustris (L.) Besser “Bog Yellow-Cress”

Rorippa palustris (L.) Besser “Bog Yellow-Cress” is known in Golden s.l. from only one collection at the Magic Mountain archeological dig. There are a few other collections in Jefferson County, including the author's collection at Ranson/Edwards and a collection at Rocky Flats. Colorado collections are scattered around the state, though not out on the eastern plains.

Originally treated as a variety of Sisymbrium amphibium by Linnaeus (1753), it was elevated to rank of species by Leysser (1783), and moved to Rorippaby Besser (1822).

Rorippa sinuata (Nutt.) Hitchc. “Spreading Yellowcress”

First published as Nasturtium sinuatum Nutt. ex. Torr. & A. Gray (1838). Collections by Nuttall are from his Arkansas and overland trail trips. Moved to Rorippa by Hitchcock (1894) Spring Flora of Manhattan without comment or explanation. The Manhattan referred to is the one in Kansas.

It seems a little suspicious to me that there is one collection each of three different Rorippa in Golden s.l. Of course, mine is correctly identified.

Rorippa tenerrima Greene “Modoc Yellowcress”

Known from only one collection on North Table Mountain by the author, Rorippa tenerrima Greene “Modoc Yellowcress” and this is the first collection in Colorado since 1910. The plant was more commonly found between 1897 and 1910 along waterways in northern Colorado.

The species was described by E. L. Greene (1895b) from collections made in Modoc County, California.

Turritis glabra L. “Tower Rockcress”

Collected sparingly in Golden s.l., only in the Survey Field and Apex Park, with a report from North Table Mountain. Mostly along the base of the Front Range, with one collection in the interior foothills. Generally known from the Colorado Front Range to the west.

Cleomaceae Bercht. & J. Presl. — Bee Plant Family

Cleomella serrulata (Pursh) Roalson & J. C. Hall “Rocky Mountain Beeplant”

There is one collection, made at Heritage Square by Ernest H. Brunquist in connection with the Peabody Museum archeological dig. There is also a report from North Table Mountain, and an observation by the author in Tucker Gulch near the 1st Street bridge. Jefferson County collections are distributed along the base of the Front Range. Otherwise, collections in the state are well-distributed to the counties.

First described by Pursh (1814) from a Lewis & Clark collection, it was placed in Peritoma by deCandolle (1824). It resided there until phylogenetic data suggested it was best placed in Cleomella s.l. (Roalson, et al., 2015).

Polanisia dodecandra (L.) DC. “Sandyseed Clammyweed”

One collection in Golden s.l., by Loraine Yeatts on South Table Mountain. Jefferson County locations are along the base of the Front Range and then up Clear Creek Canyon. Colorado state collections are mostly along the base of the Front Range, and then out on the eastern plains, with a few collections scattered in the mountain interior.

First named Cleome dodecandra L., then placed in Polanisia Raf. by deCandolle (1824).

Sedum lanceolatum Torr. “Spearleaf Stonecrop”

“Spearleaf Stonecrop” — Sedum lanceolatum Torr. — is the common succulent along the Front Range. In Golden s.l., it has been collected on South Table Mountain and in the mouth of Clear Creek Canyon, and observed on North Table Mountain and other places. It is probably one of those very common plants that are often overlooked by collectors.

Sedum lanceolatum Torr. was first collected by Edwin James MD, botanist of the Stephen Long expedition of 1820. James did not record the collection in his diary, so we only know it was collected somewhere in Jefferson, Douglas, or El Paso Counties. John Torrey (1827) described the plant in his first account of plants collected on the Long expedition.

This little succulent has been collected throughout Jefferson County, though more intensely in the northern part of the county. The author has collected it at Ranson/Edwards, Clear Creek Canyon, and the Buffalo Creek Recreation Area. Colorado collections are mostly from the Front Range westward.

Jamesia americana Torr. & A. Gray “Fivepetal Cliffbush”

“Fivepetal Cliffbush” — Jamesia americana Torr. & A. Gray — is found in the mouth of Clear Creek Canyon and on Lookout Mountain. The best place to see it in Golden is on the Peaks to Plains Trail at the Tough Cuss Bridge across Clear Creek. The plant is more common at higher elevations throughout the foothills region of Jefferson County and generally found along in the Front Range of Colorado.

Our plant was first collected by Edwin James, M.D. in 1820. James was the botanist on the Stephen H. Long expedition, the first scientific expedition to explore the Front Range of Colorado. They ascended the South Platte River and camped at mouth of Clear Creek at the South Platte on July 4th, 1820. Seeing the mountains in the distance they ascended Cannonball Creek (now Clear Creek) but became discouraged when, at Inspiration Point, the mountains still appeared far in the distance. Traveling south, they climbed Pikes Peak, saw the Royal Gorge, and followed the Arkansas River as far as Rocky Ford where they turned south for New Mexico.

Unfortunately, James failed to record the location that he found our plant, so the collection could have been made anywhere from Adams County south along the Front Range to Fremont County. John Torrey M.D. and Asa Gray, M.D. wrote about our plant in the 1840 edition of their Flora of North America.

All three of these men, Edwin James, John Torrey, and Asa Gray, were medical doctors as were many of the botanists during this era. The study of botany was regarded as an essential component of medical training from the early 18th century until early in the 20th century because plants were the main source of medicine.

Coll. No. 2236, Jamesia americana.

Heuchera bracteata (Torr.) Ser. “Bracted Alumroot”

One collection on Lookout Mountain, and several observations along the Gateway segment of the Peaks to Plains Trail and the Welch Ditch. Jefferson County collections are scattered in the foothills in the north part of the county. Nearly all Colorado state collections are found in the Front Ranges north of Cañon City. Native to Colorado and Wyoming.

Described by Torrey (1828) as Tiarella? bracteata from a collection by Dr. Edwin James someplace between Platte Canyon and Pikes Peak. Placed in Heuchera as H. bracteata by DeCandolle (1830, v. 4, p. 52).

Habitat of Coll. No. 2826, Heuchera bracteata.

Heuchera parvifolia Nutt. ex Torr. & A. Gray “Littleleaf Alumroot”

Found on or below cliffs of North and South Table Mountains, usually in damp places. Also known from Rocky Flats and Chatfield.

Published by Torrey & A. Gray (1838) from a manuscript by Thomas Nuttall. Collections noted by Nuttall in the Blue Mountains of Oregon and by Dr. Edwin James in the Rocky Mountains.

Micranthes rhomboidea (Greene) Small “Diamondleaf Saxifrage”

Found occasionally on upper slopes of North and South Table Mountains, Lookout Mountain, and Apex Park. Found along the foothills of Jefferson County, north of Conifer or Aspen Park. Found at various places in the Rocky Mountains on both east and west slopes.

Described first by Greene (1898) as Saxifraga rhomboidea, then referred to Micranthes rhomboidea by Small (1905).

Ribes aureum Pursh “Golden Currant”

Ribes aureum Pursh — “Golden Currant” — is common on slopes of Golden s.l. I have collected it on North Table Mountain, in Kinney Run, and Apex Park. It has also been seen or collected on South Table Mountain and Windy Saddle Park. It is generally found alond the foothills of the Front Range in Jefferson County, and scattered through most areas of Colorado, except the highest mountains.

Described by Pursh (1814) from Lewis & Clark collections and garden-grown specimens that he had seen.

Ribes cereum Douglas “Wax Currant”

Very common small shrub in Golden s.l., “Wax Currant” — Ribes cereum Douglas — has been collected in all identified localities within the city. Known from nearly all places in Jefferson County, and nearly every county of Colorado.

Described by David Douglas (1830) from plants grown from seed he took to England in October 1827. He described the plant as occurring along the Columbia River from the Great Falls to the sources in the Rocky Mountains.

Native Rosaceae — Rose Family

Amelanchier alnifolia (Nutt.) Nutt. ex M. Roem. “Saskatoon Serviceberry”

Amelanchier alnifolia (Nutt.) Nutt. ex M. Roem. “Saskatoon Serviceberry” and the related Amelanchier utahensis Koehne are found occasionally around Golden.

Around Golden, the author has collected A. alnifolia at North Table Mountain, Tin Cup Ridge, and Dakota Ridge. Loraine Yeatts made several collections at South Table Mountain, and there is one collection in Chimney Gulch by Hazel Schmoll. The specimens seen by the author are all quite small, usually on the order of one meter tall and the same in diameter.

There are also two collections of A. utahensis, one from Lookout Mountain, and one from “hog back near Golden.” This could be Dakota Ridge (North Hogback) or Tin Cup Ridge, the northward extension of Dinosaur Ridge into Golden. The author has not seen this serviceberry in Golden, but is familiar with it from collections made in eastern California.

Saskatoon Serviceberry has been collected sparingly around Jefferson County. In Colorado, it is found from the Rocky Mountain Front Range and in montainous areas to the west. On a national basis, be serviceberry is found in western North America.

Some authors, such as Ackerfield (2015), treat A. utahensis as a variety of A. alnifolia, explaining that the two taxa overlap in morphology and distribution, and that it can be difficult, if not impossible, to assign one name or the other to some specimens. For A. alnifolia the leaves are larger, usually glabrous, the petals are larger, and there are usually 5 styles.

The author citation “(Nutt.) Nutt. Ex M. Roem.” is curious. It seems that Nuttall (1818) first published Aronia alnifolia Nutt. from plant he saw in 1811 near Fort Mandan. Then Nuttall (1834a) used the name Amelanchier alnifolia Nutt. from plants collected for him by Nathaniel Wyeth in 1833. It would seem that he accepted that the taxon should be in Amelanchier, but his simple listing of the name without specifying the basionym (a first name for the taxon) was an invalid naming, or nom. inval. It was not until Roemer (1847) that Amelanchier alnifolia was validly published from a description by Nuttall.

Coll. No. 2253, Amelanchier alnifolia	Habitat of Coll. No. 1800, Amelanchier alnifolia

Amelanchier utahensis Koehne “Utah Service-Berry”

Two collections, one on Lookout Mountain and another on a hogback near Golden. Other Jefferson County collections tend to be up in the foothills. More common on the west slope of Colorado.

Koehne (1890) description is not readily available. Our Flora of Colorado (Ackerfield, 2015) treats our plant as a variety of A. alnifolia, whereas other sources, e.g., FNANM and POWO, treat them as distinct species. To distinguish the two, for A. utahensis the leaves are smaller and usually hairy above, the petals are smaller, and there are fewer style, usually only 2-4, rarely 5.

Cercocarpus montanus Raf. “Alder-Leaf Mountain Mahogany”

Collected or reported in every open space of Golden s.l.. Perhaps undercollected because of its commonality. Found throughout Jefferson County. Common on Colorado dry hillsides, oftern with pinyon-juniper, oaks, ponderosa pines, or Douglas fir, 4,000 to 9,500 ft.

Described by Rafinesque from a specimen collected by Edwin James of the Long Expedition, 1820, probably in present Jefferson County, Colorado. Rafinesque was somewhat frustrated by Torrey's reluctance to publish a new species name in assigning James' collection to C. fothergillides Humb. Bonpl. And Kunth.

Coll. No. 2270.1, Cercocarpus montanus in bloom.

Crataegus erythropoda Ashe “Cerro Hawthorn”

Crataegus succulenta Schrad. ex Link “Fleshy Hawthorn”

Common along streams or gulches in Golden s.l., e.g., Kinney Run below Eagle Ridge. Found primarily along the base of the Front Range in Jefferson County. Colorado state distribution is similar, along the base of the Front Range north of Palmer Lake, and then scattered in other parts of the state.

Fragaria virginiana Mill. “Virginia Strawberry”

One collection “… above Golden …,” a few more collections in Jefferson County from Meyer Ranch in the north to Lost Creek Wilderness in the south. Quite common in the higher mountain ranges of Colorado, including two collections by the author in Lake County near Leadville.

Described by Miller (1768, 8th ed.), with little comment, probably from Virginia. Its native range is eastern Canada to northern and eastern U.S.A. and northern Mexico.

Holodiscus discolor var. dumosus

Holodiscus dumosus (Nutt. ex Torr. & A. Gray) A. Heller “Rock Spiraea”

Rock Spiraea — Holodiscus dumosus (Nutt. ex Torr. & A. Gray) A. Heller — is found occasionally on rocky slopes. Expected mainly on canyon slopes, such as such as those along Welch Ditch in the mouth of Clear Creek Canyon, it is also found on the west-facing slope of North Table Mountain, and the east-facing slope of Eagle Ridge.

Most of the Jefferson County collections are near Golden, though there are two collections in southwest Jefferson County. More broadly in Colorado, it is found throughout the southern Rocky Mountains

To borrow from Kermit and Cookie Monster of Sesame Street, the hoped-for rectangle of nomenclature and taxonomy in Holodiscus is a wreck and a tangle. Weber & Wittmann (2012) accept only H. discolor, whereas Ackerfield (2015) accepts only H. dumosus. Meanwhile, Lis (2015) in his recently published treatment of Holodiscus in Flora of North America reduces H. dumosus to a variety of H. discolor. To be sure, the history of these names is a kind of mess, in part, for example, because Nuttall's manuscript describing H. dumosus was mentioned Torrey & Gray's (1838) Flora of North America but not published until 1847 in Hooker's London Journal of Botany.

I think similarly the common name of “Rock Spiraea” is unfortunate because it conflicts with the more-descriptive use of the same common name for Petrophytum caespitosum (Nutt.) Rydb.

Physocarpus monogynus (Torr.) J.M. Coult. “Mountain Ninebark”

Found in the foothills and on slopes of the mesas generally in a slightly more moist or protected location.

Described by John Torrey (1828) as Spiraea monogyna from an Edwin James, MD, collection July 7, 1820, in ravines of the foothills of Sheep Canyon on the north side of South Platte Canyon. Placed in the genus Physocarpus by Coulter (1891)

Habitat of Physocarpus monogynus on North Table Mountain.	Coll. No. 1658, Physocarpus monogynus	Coll. No. 1397, Physocarpus monogynus

Potentilla fissa Nutt. ex Torr. & A.Gray “Bigflower Cinquefoil”

Collected on most mesas, mountains, and ridges around Golden s.l.. Found throughout Jefferson County and probably more common that the number of collections (48) would indicate.

Published in Torrey & A. Gray's (1838) Flora of North America from an manuscript written by Thomas Nuttall. Recent phylogenetic work suggests that this is one of several Potentilla that should be treated as a Drymocallis.

Coll. No. 1911, Potentilla fissa

Potentilla gracilis Hook. “Slender Cinquefoil”

Known in Golden s.l. from only a single report on North Table Mountain (Zeise, 1976). There is a collection from Rocky Flats, and additional collections from the foothills in the interior of the county. Most Colorado state collections are in the interior Rocky Mountains.

The species was described by Hooker (1830)

Potentilla norvegica L. “Norwegian Cinquefoil”

Collected on top of North Table Mountain on the west side of Vaca Lake. Jefferson County collections are in wet areas in the northern part of the county. Colorado state collections are along the Front Range, a little out on the Palmer Divide, and then scattered around the state, except for northwest Colorado.

Described by Linnaeus (1753) who knew it from Norway, Sweden, and Canada; its native range is subartic and subalpine nothern hemisphere.

Potentilla pensylvanica L. “Prairie Cinquefoil”

One collection on the north side of North Table Mountain where it is quite common. Other Jefferson county collections are at the Majestic View Nature Center and the Flying J Ranch Park. Most Colorado collections are in the mountains.

Described by Linnaeus (1767) from Canada. We now consider it native to Spain, Italy, eastern Europe to Mongolia, subarctic America to west and central Europe.

Potentilla rivalis Nutt. “Brook Cinquefoil”

One collection by the author at Vaca Lake on top of North Table Mountain. There are seven collections in Jefferson County, most at Rocky Flats, but also one by the author at Ranson/Edwards Homestead Open Space.

Described in Torrey & A. Gray (1838) Flora of North America from a Thomas Nuttall manuscript. Nuttall gives the location as along the Lewis River. Both the present-day Snake River and the Salmon River have been called the Lewis River.

Ertter and Reveal (FNANM, 1993+) write in their discussion of Potentilla section Rivales that Potentilla rivalis is one of several similar-appearing Potentilla the others being P. norvegica, and P. supina. So similar that they have at times been placed in a single group, such as Tridophyllum (E. L. Greene, 1906). As it happens, I have collected all three species in northern Jefferson County, P. norvegica and P. rivalis on North Table Mountain, and P. rivalis and P. supina (ssp. paradoxa) at Ranson/Edwards Homestead Open Space Park. However, the physical similarity is not supported by molecular data, which instead scatters Potentilla norvegica, P. rivalis, and P. supina among the core Potentilla. Ertter and Reveal further state that existing herbarium annotations of P. biennis, P. rivales, and P. norvegica are not reliable, although the three species can be readily be readily distinduighed by the vestiture of proximal petioles and stems.

Coll. No. 1682.1, Potentilla rivalis	Ternate leaf of Coll. No. 1682.1, Potentilla rivalis

Prunus americana Marshall “American Plum”

Prunus (cherry, peach, and plum) is distinguished from Malus (apple) by the superior ovary and fruit in the form of a drupe.

P. americana has a reddish fruit which can be distinguished from the blue-purple fruit of P. domestica “European Plum.”

Described by Marshal (1785) in his catalog of American forest trees and shrubs.

Coll. No. 2443, Prunus americana	Coll. No. 2443, Prunus americana

Prunus pensylvanica L. f. “Pin Cherry”

Several collections of this native cherry, on North and South Table Mountains, Schweich Hill, and Lookout Mountain. There are a few other collections in the county, mostly near Golden s.l., but also one in Golden Gate Canyon State Park and another southwest of Evergreen. Colorado state collections are along the Front Range with a few on the edges of mountains in the southern state.

Described by Linnaeus (1782) in his Supplementum as living in northern America. Now (Kew, 2022) known to be native to subartic America to United States, including Colorado, but not Utah, New Mexico, or Kansas and Nebraska.

Coll. No. 1354, Prunus pensylvanica

Prunus virginiana L. “Chokecherry”

Very common in Golden s.l., Prunus virginiana L. “Chokecherry” is found in all open spaces and the mesas and hogbacks. It is found throughout the county. Colorado state collections are found throughout the state, including a few out on the plains.

Described by Linnaeus (1753) as living in Virginia, its native range is subarctic America to north, central, and eastern U.S.A.

Rosa L. “Rose”

We have three, or maybe four, taxa of Rosa L. native to Colorado and found in Jefferson County. Our current Flora of Colorado (Ackerfield, 2015) recognizes three taxa: R. arkansana, R. blanda, and R. acicularis ssp. sayi. R. woodsii is placed in synonomy with R. blanda. Our penultimate flora (Weber & Wittmann, 2012) recognized R. arkansana, R. sayi, and R. woodsii, with no mention of R. blanda.

Rosa acicularis Lindl. ssp. sayi (Schwein.) W. H. Lewis “Say's Acicular Rose”

Three collections, one by the author in the survey field; the other two at some level of Lookout Mountain. Jefferson County collections are in the lower Front Range foothills or at their base. Colorado state collections are scattered around the state from the Front Range to the west.

R. acicularis ssp. sayi is the North American subspecies of the Eurasian R. acicularis. Therefore anything properly determined R. acicularis in Colorado should be referred to subspecies sayi. Thomas Say was the zoologist on the Stephen H. Long expedition to the Rocky Mountains of 1820.

Rosa arkansana Porter “Prairie Rose”

The Prairie Rose — Rosa arkansana Porter — is common in Golden s.l., collected or reported on North and South Table Mountains, Schweich Hill, and Heritage Square. Most Jefferson County collections are on the plains in the northern part of the county. Colorado state collections are along the Front Range, with a few out on the plains, and a few in the lower elevations of the mountains.

Named by Porter (1874) for the collecting location on the banks of the Arkansas River near Cañon City by Townshend Brandegee, but also seen in the Raton Mountains and Texas.

Coll. No. 1670, Rosa arkansana

Rosa woodsii Lindl. “Mountain Rose”

Just a few collections, one on Eagle Ridge, the other in Vidler's Gulch, and one on Clear Creek. Jefferson County collections are scattered throughout the county, out on the plains and up in the foothills. Most Rosa woodsii collections in Jefferson County are undetermined as to subspecies. The few that are have been determined subsp. woodsii

There are many Colorado state collections, mostly in the mountains, but a few out on the plains. At the state level, nearly 2/3 are not determined to infraspecific names, and about 1/4 are determined variety ultramontana (SEINet, 2022).

The plant was described from plants grown from seed by J. Sabine, Royal Horticultural Society. While the location of the seed collection was described as near the Missouri River, the collector was not named. The name was published by Lindley in his Rosarum monographia, honoring Joseph Woods, an English Quaker architect, botanist and geologist born in the village of Stoke Newington, a few miles north of the City of London. The genus of ferns, Woodsia, is also named for Joseph Woods.

FNANM (1993+) proposes five subspecies, including ultramontana, see Lewis & Ertter (2007) for an explanation.

Rubus deliciosus Torr. “Delicious Raspberry”

Rubus deliciosus Torr. “Delicious Raspberry” is very widely distributed throughout Golden s.l. from North and South Table Mountains on the east to Windy Saddle and Apex Parks on the west. Similarly, the plant is widely distributed in Jefferson County. At the state level, it is found throughout the central Rocky Mountains with an additional cluster in the Unaweep Canyon area of Mesa County.

Described by Torrey (1828) from collections by Dr. Edwin James; no date or location data available. Weber & Wittmann (2012) state that the collections were made at the mouth of Boulder Canyon. This is highly unlikely as there is no indication that Dr. James, or anyone else in Major Long's party were anywhere near Boulder Canyon.

Rubus idaeus L. var. strigosus (Michx.) Maxim. “American Red Raspberry”

A small number of collections from mountain slopes on the west side of Golden s.l. There are a few collections in Jefferson County, from the interior of the foothills to the highest plains, i.e., Rocky Flats. Colorado state collections are mostly from the interior core of the Rocky Mountains.

First described by Michaux (1803) as Rubus strigosus from the mountains of Pennsylvania and from Canada. Rubus idaeus is the source of most of the cultivated red and amber raspberries.

There are many names published for this plant and much dissonance between them. I am following our current Flora of Colorado (Ackerfield, 2015). Weber & Wittmann (2012) accept R. idaeus L. ssp. melanolasius (Dieck) Focke, whereas FNANM (1993+) and Kew (POWO, 2022) accept Rubus idaeus L. subsp. strigosus (Michx.) Focke.

Astragalus agrestis Douglas ex G. Don. “Purple Milkvetch”

Fairly common around Golden s.l., Astragalus agrestis Douglas ex G. Don. “Purple Milkvetch” has been collected on North and South Table Mountains, the Colorado School of Mines Survey Field, and in smaller open spaces such as the Schweich Hill. It generally forms small colonies in short grasses, and is easily recognized by its upright capitate inflorescence.

Jefferson County collections are on the plains at the base of the Front Range. At the Colorado state level, this milkvetch is found along the Front Range, a few out on the plains, and in the interior valleys of the mountains.

The plant was first described by George Don (1832) from a manuscript written by David Douglas. Historical herbarium records suggest the plant was first collected in Colorado by Hall & Harbour (their no. 139) and by Charles C. Parry in their expedition of 1862. We really don't know where in Colorado these collections were made.

Coll. No. 1402, Astragalus agrestis	Coll. No. 1398, Astragalus agrestis

Astragalus crassicarpus Nutt. “Groundplum Milkvetch”

This interesting milkvetch has an inflated fruit that look like large grapes or small plums. It is widespread around Golden, but not often seen. The best time to see this milkvetch in the field is mid- to late-May. When dry the fruits are still recognizable, just brown and hard.

First collected by Thomas Nuttall “ … above the River Platte … ” probably in 1811, it was published in a list of plants for sale from the garden of John Fraser in London (Nuttall, 1813).

Astragalus crassicarpus “Groundplum Milkvetch”	Habitat of Astragalus crassicarpus on North Table Mountain.

Astragalus drummondii Dougl. ex Hook. “Drummond's Milkvetch”

Astragalus drummondii Dougl. ex Hook. — “Drummond's Milkvetch” — is common in Golden s.l. Being a tall milkvetch with white flowers, it is easy to recognize in the field.

Jefferson County collections are mostly on the plains adjacent to the Rocky Mountains front range. Colorado collections are on the prairies and slopes of central Colorado.

Described by Hooker (1831) from a David Douglas collection and manuscript.

Fruit of Coll. No. 1141, Astragalus drummondii

Astragalus flexuosus G. Don “Flexible Milkvetch”

A common milkvetch, Astragalus flexuosus G. Don “Flexible Milkvetch,” has been collected in most Golden s.l. open spaces, though not all. It is usually found climbing on other forbs or subshrubs.

First described by George Don (1832), a Scottish botanist and plant collector, probably from plants grown from seed sent by David Douglas, collected near the Columbia River.

Jefferson County collections are from the northern part of the county, into the foothills as far as Centennial Cone. Colorado collections are generally from the foothills west and south, at lower elevations.

Astragalus laxmannii Jacq. var. robustior (Hook.) Barneby & S. L. Welsh “Prairie Milkvetch”

Astragalus laxmannii Jacq. var. robustior (Hook.) Barneby & S. L. Welsh “Prairie Milkvetch” is found occasionally in the intensely collected open spaces of North and South Table Mountains, and Heritage Square.

Jefferson County collections are along the Front Range and up into the foothills as far south as the Buffalo Creek Recreation Area. The Colorado distribution includes the Front Range, shortgrass prairie, and mountain valleys.

The species was first described by Jacquin (1776) and named for a patron of the Vienna Botanic Garden, Eric Laxmann. While Jacuin knew it from plants grown from seed from Imperial Russia, Pallas (1800) described it as A. adsurgens from Trans-Baikal to Mongolia. Hooker (1831) recognized the two species were the same, but left it as A. adsurgens while naming a variety robustior from the mountain valleys on the west slope of the Rocky Mountains using a manuscript by David Douglas. Barneby & Welsh (1996) published A. laxmannii var. robustior pertmiing us to use the A. laxmannii name of priority.

Astragalus parryi A. Gray “Parry's Milkvetch”

There is one report of Astragalus parryi A. Gray “Parry's Milkvetch” on North Table Mountain, and a collection by Ira W. Clokey on Lookout Mountain determined A. parryi, whereas possible duplicates are determined A. agrestis. Presence of A. parryi should be considered doubtful unless confirmed.

Astragalus shortianus Torr. & A. Gray “Short's Milkvetch”

Astragalus shortianus Torr. & A. Gray “Short's Milkvetch” is found occasionally, with collections on North and South Table Mountains, plus I have found it on Tin Cup Ridge and in Kinney Run.

The plant was described by Torrey & Gray (1840) from a manuscript by Thomas Nuttall. Nuttall saw it in the “Rocky Mountains, towards the plains of the Oregon.”

Dalea candida Willd. “White Prairie Clover”

Dalea candida Willd. “White Prairie Clover” is less common than the next, Dalea purpurea, but still found on North and South Table Mountains.

Described by Wildenow (1800, t. 3, pt. 2, p. 1337) in his 4th edition of Linnaeus' Species Plantarum

Dalea purpurea Vent. “Purple Prairie Clover”

“Purple Prairie Clover” — Dalea purpurea Vent. — is not particularly common in Golden s.l. either, having been collected on North Table Mountain, Heritage Square, and the Survey Field, but not on South Table Mountain.

Jefferson County collections are generally along the base of the Front Range foothills. Colorado collections are also along the Front Range foothills and out on the plains, with a scattering of collections in the mountain valleys.

The plant was found in Illinois by Michaux, who sent seeds (or plants?) to Jacques Cels who cultivated foreign plants in Paris. Etienne P. Ventenat (1800) described the plants in Cels' garden, illusteated by Pierre-Joseph Redoute.

Inflorescence of Coll. No. 1197, Dalea purpurea

Glycyrrhiza lepidota Pursh “American Licorice”

Collected or observed on North and South Table Mountains and at Tin Cup Ridge. Likely in all Golden s.l. open spaces. Collections of the plant have been made throughout Colorado though most commonly along the Front Range foothills from Colorado Springs north, where it is usually found along natural or artificial watercourses and on floodplains.

Nuttall (1818) credits John Bradbury as first detecting this plant around Saint Louis. Though a name for the plant was first published by Nuttall (1813) this name is treated as invalid, and we use Pursh's (1814) name.

Coll. No. 1222, Glycyrrhiza lepidota

Hedysarum boreale Nutt. “Utah Sweetvetch”

Native to, and found elsewhere, in Jefferson County, though not in Golden s.l. except when planted. State collections mostly on the western slope, and the plains south of Colorado Springs.

First collected near Fort Mandan on the Missouri River by Thomas Nuttall and published by him in 1818.

Ladeania lanceolata (Pursh) A. N. Egan & Reveal “Dune Scurfpea”

Known from two historic collections, Ladeania lanceolata (Pursh) A. N. Egan & Reveal “Dune Scurfpea” is possibly extirpated from Golden s.l. One of the historic collections was made by E. L. Greene in 1872. The location is simply “Golden City,” as Golden was known then. The other historic collection was made by J. R. Churchill in 1918, with location of “Golden, railroad track.”

There is one other collection of this plant from Jefferson County, that of Lincoln Constance and Reed Rollins, made June 24, 1937, near Mount Morrison. Colorado collections are scattered around the plains and interior valleys, including northwest Colorado. The author has collected this plant at Alameda Well, Mono County, California, suggesting that it might be a Cordilleran plant, except that it is found out on the plains as far east as central Nebraska and Kansas.

The plant was first described by Pursh (1814) as Psoralea lanceolata. Then Rydberg (1919) moved it to Psoralidium lanceolatum. For a long time, the sheet described by Pursh (1814) was thought to be a Lewis & Clark collection. However, Reveal et al. (1999) showed that this sheet could only have been gathered by Thomas Nuttall in 1811. Egan & Reveal (2009) proposed Ladeania lanceolata to accommodate taxa left behind when Psoralidium tenuiflorum (Pursh) Rydberg was transferred to Pediomelum Rydberg because of previously published evidence on phylogenetic relationships.

Lathyrus eucosmus Butters & H. St. John “Bush Vetchling”

Lathyrus eucosmus Butters & H. St. John “Bush Vetchling” has been collected on North and South Table Mountains.

Mostly out on the plains away from the foothills. Colorado collections are mostly from Denver south and along the southern border of the state. The plant is mostly know from Colorado, New Mexico, and Arizona, with a few collections in Utah.

It was described by Butters & St. John (1917) in a paper that was (im my mind) intended to clarify relations between the various Lathyrus of the New World. While the type was designated as a collection by A. A. & E. Gertrude Heller, no. 3658, Santa Fe, New Mexico, the plant was also collected by Edwin James (1820) and A. Fendler (1847) both in New Mexico.

Lathyrus lanszwertii Kellogg “Lanszwert's Pea”

Two collections and an observation from North and South Table Mountains, and Apex Gulch.

About half of the specimens from Jefferson County are determined variety leucanthus, whereas the remainder are undetermined to infraspecific names. The author collected one at Lippincott Ranch and put the variety name laetivirens (Greene ex Rydberg) S. L. Welsh on it. It is a question of the shape and length of the tendril.

Lupinus argenteus Pursh “Loosely Flowered Silver Lupine”

The “Loosely Flowered Silver Lupine” — Lupinus argenteus Pursh — has been found in every open space in Golden s.l. except South Table Mountain.

Jefferson County collections are found from the base of the Rocky Mountain foothills up into the Front Range. There was just one collection as far south as the Buffalo Creek Recreation Area. That collection is determined var. rubricaulis. In 2021, the author collected a small lupine along Morrison Creek that he thinks is variety fulvomaculatus. The Lupine is found throughout Colorado, except on the eastern plains. It is also found across the American Cordillera.

A Lewis & Clark collection on the Kooskoosky (Clearwater) River was described by Pursh (1814). Plants Of The World (Kew, 2022) accepts 8 varieties, five of which occur in Colorado, and a somewhat different five varieties occur in California.

Lupinus caudatus Kellogg “Kellogg's Spurred Lupine”

It is not clear whether Lupinus caudatus Kellogg “Kellogg's Spurred Lupine” occurs in Golden s.l. or not. There is one collection on Lookout Mountain that may be in Golden s.l. In the meantime, the author has collected the lupine twice in northern Jefferson County, at Ranson/Edwards and at Lippincott Ranch.

Of those collections of Lupinus caudatus in Jefferson County determined to an infraspecific name, nearly all are determined var. argophyllus. The name was first applied by A. Gray (1848) to a collection by Augustus Fendler in Santa Fe, New Mexico, in 1847.

It is looking like our variety argophyllus will be moving to L. argenteus Pursh from L. caudatus Kellogg (Allred, 2020).

Oxytropis lambertii Pursh “Purple Locoweed”

Oxytropis lambertii Pursh “Purple Locoweed” is a very common spring wildflower along trails and in Golden open spaces. The plant has compound silvery-hairy leaves at the base and one or more stalks with clusters of pea-shaped deep pink to purple flowers that later turn blue. The flowers become silvery-hairy seed pods called legumes. Some common names that wildflower books attribute to O. lambertii include "Colorado locoweed," "Lambert locoweed," "locoweed," "purple locoweed," "stemless locoweed," and "woolly locoweed."

Oxytropis and some Astragalus get their “Locoweed” name because they are toxic to cattle, sheep, horses, elk, and dogs. All plant parts contain Swainsonine, an indolizide alkaloid that inhibits an enzyme essential for normal sugar metabolism in cells, adversely affecting all body systems. It is currently thought that the Swainsonine is produced by a fungus that lives inside the rather than by the plants themselves.

Our plant is known from a published account by Frederick Pursh (1814) in his Flora Americae Septentrionalis or “North American Flora.” Pursh wrote that he saw the plant growing in the London, England garden of Aylmer B. Lambert. Pursh resided at Lambert's estate while writing his Flora, and Pursh named the plant for his benefactor. The plants in Lambert's garden were grown from seed collected by John Bradbury in 1811 along the Missouri River. Bradbury was exploring America's newly acquired Louisiana Territory under the sponsorship of the Edinburgh, Scotland botanic garden. He returned to Scotland via New Orleans as the War of 1812 was brewing.

The first plant collection made in Golden was of Purple Locoweed. Edward L. Greene, an Episcopalian minister from Denver made the collection here on May 1, 1870. After years of plant study in Colorado, Greene moved to California where he became the first professor of botany at the University of California. Greene later moved east, and his Golden collection of Purple Locoweed is now at Brown University.

Purple Locoweed (Oxytropis lambertii) on top of North Table Mountain.

Oxytropis sericea Nutt. ex Torr. & A. Gray “White Locoweed”

There is only one collection of Oxytropis sericea Torr. & A. Gray “White Locoweed” in Golden s.l., made by Stan Smookler near Castle Rock. There are a few other collections of this taxon in Lakewood and Morrison that give confidence that it is O. sericea rather than the much more common O. lambertii. The two species are known to hybridize.

The plant was described in Torrey & A. Gray (1838) Flora of North America from a manuscript written by Thomas Nuttall.

Jefferson County collections are mostly from the base of the Front Range, with one at Flying J Ranch. Colorado collections are scattered around the state from the far eastern plains, to mountain valleys, and northwest Colorado.

Pediomelum tenuiflorum (Pursh) A. N. Egan “Slimflower Scurfpea”

Another common forb found in nearly all Golden s.l. open spaces, Pediomelum tenuiflorum (Pursh) A. N. Egan “Slimflower Scurfpea” is found right along the base of the foothills. First collected by Lewis & Clark on the Big Bend of the Missouri and named Psoralea tenuiflora by Pursh (1814), it was for a time known as Psoralidium tenuiflorum (Pursh) Rydberg, until molecular genetic data showed that it really belonged in Pediomelum tenuiflorum (Pursh) A. N. Egan & Reveal (2009). Colorado collections are found mostly from the base of the Front Range east across the plains.

Pediomelum tenuiflorum

Thermopsis rhombifolia var. divaricarpa (A. Nelson) Isely “Spreadfruit Goldenbanner”

Found mostly meadows or somewhat mesic sites among the ridges and mesas around Golden s.l., such as North and South Table Mountains, and Tin Cup Ridge. Widely distributed throughout Jefferson County, sometimes in small colonies.

There are three different forms of this plant in Colorado, distinguished by the shape of the fruit. Sometimes the three forms are treated as varieties of a single species, sometimes as species in their own right. In Golden s.l., the fruit sticks straight out from the stem, or is maybe curved upwards slightly. This would be the form divaricarpa, originally proposed by Aven Nelson (1898). Our current Flora of Colorado (Ackerfield, 2015) treats divaricarpa as a variety of Thermopsis rhombifolia.

Thermopsis rhombifolia var. divaricarpa, in flower, no fruit yet.	Patch of Thermopsis rhombifolia var. divaricarpa, Coll. No. 1347.

Vicia americana Willd. “American Vetch”

Commonly encountered around Golden s.l., Vicia americana Willd. “American Vetch” has been found on North and South Table Mountains, the Survey Field, and Tin Cup Ridge. Described by Willdenow (1800) in his 4th edition of Linnaeus' Species Plantarum as living in Pennsylvania, it is considered native to nearly all of North America. It is typically found on the plains of Jefferson County at the base of the foothills. American vetch is very common in Colorado, being found in every county.

Vicia ludoviciana Nutt. “Louisiana Vetch”

Only one collection under Castle Rock on South Table Mountain, and another in Jefferson County at Chatfield. In Colorado uncommon in meadows and dry hillsides.

The plant was first described by Torrey & A. Gray (1838) from a manuscript by Thomas Nuttall. Nuttall collected the plant on the Red River, but also refers to Mr. Tainturier, a resident of New Orleans who corresponded with Hooker (Ewan, 2005). A Dr. Leavenworth also sent some material from Texas to Torrey & A. Gray

Geranium caespitosum James “Pineywoods Geranium”

Broadly distributed in Golden s.l. from North and South Table Mountains to Apex Park, Geranium caespitosum James “Pineywoods Geranium” is also widely distributed in Jefferson County, and has been found in every Colorado county except the extreme northwest and the easternmost plains.

First recognized by Edwin James, M.D., botanist on the Stephen H. Long expedition of 1820, and named G. caespitosum in James (1823), it has eleven synonyms at the specific rank, and another ten infraspecific names (POWO, Kew, 2022). In Colorado we do not accept infraspecific names for this species.

This Geranium is broadly distributed in North America, from Wyoming to Mexico, and Nevada to Texas.

Geranium richardsonii Fisch. & Trautv. “Richardson's Geranium”

There is only one collection of Geranium richardsonii Fisch. & Trautv. “Richardson's Geranium” in Golden s.l. and that one on Lookout Mountain over 100 years ago.

It is typically found in the lower foothills in the Front Range of Jefferson County, including the Lost Creek area of the southern county. Colorado collections are in the mountain areas of the state, and thus exclude to plains and the extreme northwestern and southwestern area. This geranium is found across the American Cordillera, and the author has collected it in the mouth of Lundy Canyon, Mono County, California.

First named G. albiflorum, by Hooker (1830) that name was unavailable because it was previously used by Ledebour (1829) for a Geranium in the Altai. Fischer & Trautvetter (1838) applied a name in honor of Sir John Richardson to it in 1838.

Linum lewisii Pursh “Prairie Blue Flax”

There are quite a few collections determined Linum lewisii Pursh “Prairie Blue Flax” from Golden s.l. Unfortunately, there is some confusion between this species and the non-native Linum perenne L., as well as possible hybridization between the two. L. lewisii is homostylous, i.e., the stamens and styles are approximately equal, whereas L. perenne is heterostylous, i.e., some plants have styles longer than stamens and others with styles shorter than stamens. The author confesses to being confused while in the field about determination of these two species. This is further confounded by the question of whether the two species hybridize. There is conflicting literature on this question, and development of cultivars; one in particular, “Appgar” was initially thought to be a cultivar of L. lewisii be later discovered to be a cultivar of L. perenne.

Nevertheless, Jefferson County collections of Linum that are determined L. lewisii are mostly along the base of the Front Range, with a few in the interior valleys. Colorado collections are in the mountain valleys and along the Front Range, with a very few collections on the plains.

L. lewisii was described by Pursh (1814) from a collection by Lewis & Clark, although Pursh noted that he described the plant from a live specimen, perhaps one growing in Lambert's garden.

Chamaesyce fendleri (Torr. & A.Gray) Small “Fendler's Sandmat”

Known only from South Table Mountain, Chamaesyce fendleri (Torr. & A.Gray) Small “Fendler's Sandmat,” may be more common than the number of collections would indicate.

The type was collected by Dr. J. M. Bigelow at “Big Springs of the Colorado,” collecting for the Pacific Railroad Survey in 1853, and described by Torrey & Gray (1857). This location is now known as Big Spring, Howard County, Texas, between Midland and Abilene. Dr. A. Gray had seen this plant in Fendler's New Mexico collections (his no. 800) but he did not describe any Euphorbia from Fendler's collections. Small (1903) moved this and several otherChamaesyce from Euphorbia.

Chamaesyce glyptosperma (Engelm.) Small “Ribseed Sand Mat”

More common than the preceding, there are three current collections of Chamaesyce glyptosperma (Engelm.) Small “Ribseed Sand Mat” in Golden s.l., one each from North and South Table Mountains, and one from Heritage Square.

Described by George Engelmann, M.D. as Euphorbia glyptosperma in Torrey (1859). Moved to Chamaesyce without comment by Small (1903).

KHD63968 voucher of Coll. No. 1550.5, Chamaesyce glyptosperma.

Euphorbia brachycera Engelm. “Horned Spurge”

Similar to the preceding, there are just a few collections of “Horned Spurge” — Euphorbia brachycera — in Golden s.l., on North and South Table Mountains, and another in some dry rocky soil above Deadman Gulch.

The plant was described by George Engelmann in the Mexican Boundary Survey report by Torrey (1859). Engelmann cited a collection by Charles Wright in western New Mexico.

Jefferson County collections are mostly concentrated in the northern part of the county, just up into the foothills as far as Evergreen. Colorado collections are mostly from the Front Range westward, plus a few in the Pawnee National Grassland.

Euphorbia dentata Michx. “Toothed Spurge”

Euphorbia dentata Michx. “Toothed Spurge” has been collected on North and South Table Mountains and at Heritage Square. It is also adventive in Golden gardens.

This spurge was first described by Michaux (1803) from plants found near Nashville, Tennessee. Placed by Weber & Wittmann (2012) in Poinsettia with the notation of alien, ruderal weed, whereas Ackerfield (2015) treats it as a possibly native Euphorbia.

Jefferson County collections are all right along the Front Range. Colorado collections are mainly from the Front Range east across the plains.

Euphorbia marginata Pursh “Snow on the Mountain”

There are a few collections of Euphorbia marginata Pursh “Snow on the Mountain” in the usual places of North and South Table Mountains, and Heritage Square (E. H. Brunquist). It has also been found on Eagle Ridge. The oldest collection in Golden was by N. L. Britton made 8 October 1882.

Colorado collections are mostly on the plains, with just a few collections up in the mountains.

This was a Lewis & Clark collection (28 July 1806), described by Pursh (1814, v. 2., p. 607).

Euphorbia spathulata Lam. “Warty Spurge” or “Spoonleaf Spurge”

“Warty Spurge” or “Spoonleaf Spurge” — Euphorbia spathulata Lam. — has been found on North and South Table Mountains, and nowhere else in Golden. It's pretty small, so it may be overlooked by collectors.

Collection of this little spurge were made along the base of the Front Range and just slightly into the foothills of northern Jefferson County. Colorado collections are few in number, mostly along the northern Front Range and then scattered in south-central and southwest Colorado.

Warty Spurge's native distribution is North and South America. It was described by Lamarck from a collection in “Monte-Video,” by which I assume is meant Montevideo, Uruguay.

Tragia ramosa Torr. “Branched Noseburn”

Tragia ramosa Torr. “Branched Noseburn” gives the appearance of being a small unassuming plant, but its stinging hairs pack a punch. Collections and observations are scattered around Golden s.l., on North and South Table Mountains, and from Dakota Ridge in the north to Apex Park in the south.

The plant was first described by John Torrey (1828) from collections by Edwin James, MD., botanist on the Stephen H. Long expedition of 1820. Also noted by Torrey (1859) in his report on the botany of the Mexican Boundary Survey.

Rhus glabra L. “Smooth Sumac”

One collection in Apex Park along an intermittent stream in an unnamed gulch. There should be other collections, though, such as along the Welch Ditch. There are few Jefferson County collections, those scattered from Ranson/Edwards in the north to Deckers in the south. State-wide the species is scattered along the Front Range, and the lower elevations of the San Juan Range in the southwest.

Described by Linnaeus (1753) from plants in Virginia and other North America locations.

Rhus trilobata Nutt. “Skunkbush”

Rhus trilobata Nutt. Ex Torr. & Gray “Skunkbush” is a common shrub from West Texas to southern California, and throughout the Rocky Mountain to the upper Missouri River. In the Rocky Mountain foothills near Golden, it is found everywhere, but rarely dominates the landscape. Common names are Skunkbush, Skunk Bush, Skunkbush Sumac, and Lemonade-bush. It has also been called Squawbush in the past, but that is now recognized as a perjorative name. “Lemonade”-names are probably better reserved for R. integrifolia.

First collected in the Rocky Mountains by Thomas Nuttall in 1834, it was described by Nuttall, then published by Torrey and Gray (1838) in their Flora of North America.

R. trilobata is sometimes reduced to the rank of variety or, once, subspecies under R. aromatica Aiton. See for example Watson (1871), Weber (1989), and Baldwin et al. (2012). Other authors retain R. trilobata at the rank of species, such as Barkley (1937) and our current Flora of Colorado (Ackerfield, 2015). Recent papers (Yi, et al., 2007 and Andres-Hernandez, et al., 2014) about the phylogeny of Rhus determined from molecular and structural data analyze both R. aromatica and R. trilobata as distinct species. While the studies show the two species to be closely related, the studies also show they are no more closely related than others, such as R. integrifolia and R. ovata.

Rhus trilobata at the southern end of the Survey Field.	Rhus trilobata at Ranson/Edwards.

Toxicodendron rydbergii (Small ex Rydb.) Greene “Western Poison Ivy”

Found in many places in Golden s.l., there are no collections of “Western Poison Ivy” — Toxicodendron rydbergii (Small ex Rydb.) Greene. I have never collected it, but I suppose it's time to screw up my courage, glove up, and collect. The very few collections around Jefferson County show that it is widely distributed. Similarly, the plant is widely distributed in Colorado, except the northwest corner.

First described as Rhus Rydbergii Small and published by Per Axel Rydberg (1900) in his Catalogue of the Flora of Montana and Yellowstone National Park. Greene (1905) resurrected Miller's (1754) genus of Toxicodendron and moved many Rhus American plants there.

Acer glabrum Torr. “Rocky Mountain Maple”

In Golden s.l. “Rocky Mountain Maple” — Acer glabrum Torr. has been found on the higher edges of North and South Table Mountains, and Windy Saddle Park, Apex Gulch, and the Welch Ditch. Jefferson County collections are scattered around the county, mostly in the foothills. Colorado state collections are scattered throughout the mountainous regions of the state, along streams, in gulches and ravines, and in dry forests.

Acer glabrum is a quntessential Jefferson County plant because the type was collected in Platte Canyon, Jefferson County by Edwin James MD in 1820. It was described by Torrey (1828) in his Account of a Collection of Plants by Edwin James.

Coll. No. 1738, Acer glabrum

Acer negundo L. “Box Elder Maple”

Coll. No. 2451, Acer negundo

Ceanothus fendleri A. Gray “Fendler's Ceanothus”

Found in the higher places around the edges of Golden s.l., such as Apex Park, foothills of Lookout Mountain, and Mount Vernon Canyon. Jefferson County collections are up in the foothills and the southern part of the county. Found throughout Colorado, except for the eastern plains and the northwest corner of the state.

Described by Gray (1849) from collections by Augustus Fendler in the mountains east of Santa Fe.

Ceanothus herbaceus Raf. “Jersey Tea”

Collected on South Table Mountain, though nowhere else in Golden s.l.. Other jefferson County collections with coordinates are at Rocky Flats, with non-georeferenced collections along the base of the Front Range. Most Colorado state collections are along the Front Range.

Described by Rafinesque (1808) from the Falls of the Potomac River (Virginia or Maryland).

Parthenocissus vitacea (Knerr) Hitchcock “Woodbine, Thicket Creeper”

There are a couple of collections determined Parthenocissus vitacea (Knerr) Hitchcock “Woodbine, Thicket Creeper” that were made in Golden s.l., although this taxon is difficult to distinguish from P. quinquefolia. Similarly, there are a few collections in Jefferson County, especially from the intensely-collected Chatfield Farms. Most Colorado state collections are along the Front Range with a few out on the plains and in the southwest part of the state.

It was first described as a variety of Ampelopsis quinquefolia (Linnaeus) Michaux var. vitacea Knerr, Bot. Gaz. 18: [70]. 1893. Referred to a species under Parthenocissus by Hitchcock (1894). Sometimes treated as a synonym of P. inserta (A. Kern) Fritsch, c.f., the SEINet (2022) taxon tree.

Vitis riparia Michx. “Riverbank Grape”

Growing on the banks of moist gulches, such as Apex Gulch, and on South Table Mountain. Jefferson County collections are along the base of the Front Range. Colorado state collections are also along the base of the Front Range with a few out on the plains.

Described by Michaux (1803) as “ad ripas et in insulis fluviorum Ohio, Mississipi, &c. [at the banks and in the islands of the rivers of Ohio, Mississippi, &c.].”

Sphaeralcea coccinea (Nutt.) Rydb. “Scarlet Globemallow”

Often called “Cowboy’s Delight,” found throughout Golden s.l. open spaces, sometimes as a single small delicate plant, sometimes as a larger plant with an extensive root system.

Collected first by Lewis & Clark in 1806 along the Marias River, Montana on their return from the Pacific Coast (Moulton, 1999). Collected again by Nuttall in 1811 along the Missouri River north to Fort Mandan. It was Nuttall's collection published first in Fraser's (1813) Catalogue as Malva coccinea.

Sphaeralcea coccinea (Nutt.) Rydb. On the lowest slopes of North Table Mountain.

Hybanthus verticillatus (Ortega) Baill. “Baby Slippers”

There are three collections of “Baby Slippers” — Hybanthus verticillatus (Ortega) Baill. — made in Golden s. l., two from South Table Mountain, and one from North Table Mountain. Pur plant has also been found in a private garden of about 1/2 acre in size. Moderately distributed along the base of the Front Range of Jefferson County, with collections from Roxborough State Park in the south to Rocky Flats in the north. More broadly in Colorado, the plant is found along the base of Front Range and out on the southeast plains.

The plant was first described as Viola verticillata (Ortega, 1797) from specimens grown at the Royal Gardens of Madrid using seeds sent from Mexico by D. Sesse. Baillon (1873) reorganized the Violaceae and placed our plant in Hybanthus, a genus that is highly polyphyletic. Phylogenetic work begun by Wahlert, et al. (2014) show that reorganization is necessary and that additional phylogenetic work is needed. Paula-Souza and Ballard (2014) began that work by re-establishing Pombalia and transferring our Hybanthus verticillata to it.

Viola canadensis L. “Canadian White Violet”

Found in moist canyons and below cliffs around the edges of Golden s.l., on North and South Table Mountain, and Apex and Windy Saddle Parks. Other Jefferson County collections are along the base of the Front Range, and up into the foothills of the northern part of the county. Most Colorado state collections are in the mountains west of the plains, except for northwest part ot the state.

Described by Linnaeus (1753) who stated the habitat was Canada, and credited Pehr Kalm.

Viola nuttallii Pursh “Nuttall's Violet” Viola nuttallii Pursh “Nuttall's Violet”

Commonly found in all of Golden s.l. open spaces, in nearly all habitats except the most dry and exposed. Most Jefferson County collections are in the northern part of the county along the base of the Front Range. Widespread in Colorado, common on open hills and in grasslands and meadows.

Described by Pursh (1814, v. 1, p. 174) who had seen it in Nuttall's herbarium. Nuttall collected it on the banks of the Missouri River.

Viola pedatifida G. Don “ Prairie Violet”

One collection on Lookout Mountain that may be within Golden s.l. One other collection in extreme northern Jefferson County. Otherwise it is found in gry grasslands and open ponderosa pine forest along the Front Range.

Described by George Don (1831) and known only for a North America origin.

Mentzelia albicaulis (Douglas ex Hook.) Douglas ex Torr. & A. Gray “White-Stem Blazing Star”

With two collections, one each on North and South Table Mountains, Mentzelia albicaulis (Douglas ex Hook.) Douglas ex Torr. & A. Gray “White-Stem Blazing Star” Found in more or less random places in northern Jefferson County, along the hogbacks or in the lower foothills. Scattered around Colorado, often on the edges of the valleys. The author has also collected our plant at Mono Lake, Mono County, California. Distribution in Utah and Nevada show that it could be termed a Cordilleran species.

First described by Hooker (1834) from a manuscript by David Douglas as Bartonia albicaulis, then by Torrey & A. Gray (1840) again from a manuscript by David Douglas, perhaps the same, or a copy of the same, manuscript.

Mentzelia dispersa S. Watson “Bushy Blazing Star”

There are two collections of Mentzelia dispersa S. Watson “Bushy Blazing Star”, both on the west side of the mesa, and collected within a week of each other in 1992. The other Jefferson County collections were made by George E. Osterhout and Ira W. Clokey in Morrison, a little more than 100 years ago. There are relatively very few Colorado collections, and they are scattered over the mountainous area of the state, at elevations of 4500 ft. to 9000 ft., with none on the plains.

The first recognition of M. dispersa as an entity was Watson (1871) who proposed M. albicaulis var. integrifolia S. Watson, from collections in Nevada and Utah, and a Hall & Harbour collection from Colorado. Five years later, Watson (1876) published M. dispersa as a new species, citing collections from Washington Territory to Colorado and southward, including Yosemite Valley and Isla Guadalupe, Mexico.

Mentzelia multiflora (Nutt.) A. Gray “Adonis Blazing Star”

One of five different Mentzelia collected in Golden s.l. Three collections in foothill sites, such as Clear Creek Canyon, Apex Gulch, and on Lookout Mountain.

Farther afield in Jefferson County it has been found in Genesee Park and Centennial Cone Open Space.

First published by Nuttall (1848b) from plants collected by William Gambel along the Rio Grande near Santa Fé, New Mexico. Nuttall (1848) placed this taxon in Bartonia, which is probably the Bartonia of Muhl. ex Willd. (1801) and not the Bartonia of Pursh (1812). Bartonia is still used as one of five section names of Mentzelia (Hufford, et al., 2017).

Gray (1849) in Plantæ Fendleriana, a partial catalogue of plants collected by Augustus Fendler in 1847, placed this taxon in Mentzelia multiflora (Nutt.) A. Gray.

Most authors retain all the Mentzelia s.l. in a single name (Ackerfield, 2015, and Hufford, et al., 2017). An exception is Weber & Wittmann (2012) who segregate most of the Colorado “Mentzelia” into the genus Nuttallia Raf., some into Acrolasia and only one into Mentzelia

Mentzelia nuda (Pursh) Torr. & A. Gray “Bractless Blazing Star”

There are only two collections of Mentzelia nuda (Pursh) Torr. & A. Gray “Bractless Blazing Star” in Golden s.l., both by the author, and their determination might be highly suspicious except for the historical observation on North Table Mountain. There is another collection on South Table Mountain (Yeatts, #652) with vouchers that determined variously M. nuda and M. speciosa. The other collections in Jefferson County are around Chatfield Farms, an intensely collected location. Colorado collections are mostly out on the plains, with a few up in the mountains.

Mentzelia speciosa Osterh. “Plains Blazing Star”

For Mentzelia speciosa Osterh. “Plains Blazing Star,” we have an observation on North Table Mountain and a collection on South Table Mountain, from which various vouchers have been determined M. nuda or M. speciosa. Other Jefferson County collections are from Morrison, and then up in the foothills near Pine. Colorado state collections are along the Front Range and along the edges of the southern mountain valleys.

The plant was first named M. aurea by George Osterhout (1901a) from a collection he made in Estes Park. However this name was previously used by Nuttall and was thus illegitimate, so a month later, Osterhout (1901b) proposed M. speciosa.

Echinocereus viridiflorus Engelm. “Nylon Hedgehog Cactus”

A very small beehive-shaped cactus, sometimes growing in very dense clusters. Seen on North and South Table Mountains, and Schweich Hill, where it forms dense colonies.

Found in the intensely-collected places of Jefferson County, such as Rocky Flats and Chatfield Farms. Common on the plains and mountain valleys of eastern Colorado.

Recognized as a new genus and species and published by George Engelmann (1848) from collections made at Santa Fe and on the Santa Fe Trail at Wolf Creek by Augustus Fendler in 1847.

Obs. No. 1471, Echinocereus viridiflorus

Escobaria Britton & Rose

Escobaria missouriensis (Sweet) D. R. Hunt “Missouri Foxtail Cactus”

A very low-growing cactus that is also easily overlooked or stepped upon. Unique in that the red fruits develop in the spring a year after flowering.

Found in most open spaces of Golden that have been carefully examined, usually gravelly hills or ridges that are relatively undisturbed, where populations can be dense. Location data on herbarium vouchers is typically redacted, but county data suggests the cactus is found in most counties of the state.

The “Missouri” name refers to the Missouri River that was a thoroughfare of transportation during the early 19th century, long before the State of Missouri was admitted to the Union in 1821.

The cactus was first reported by Thomas Nuttall on the Missouri River in 1811. Nuttall, however, erroneously thought it was a West Indian cactus known then as Cactus mammillaria L. Sweet (1826) recognized the difference and published the name of Mammillaria misssouriensis Sweet, a name used in Colorado as recently as 1964 (Harrington, 1954 & 1964 2ed.). Coryphantha missouriensis (Sweet) Britton & Rose was also commonly applied to this cactus. Most recently, phylogenetic data (Sanchez, et al., 2022) shows our cactus deeply embedded within Escobaria Britton & Rose.

Escobaria missouriensis

Escobaria vivipara (Nutt.) Buxb. “Beehive Cactus”

Seen in multiple places around Golden s.l., usually on ridges or rocky places, but generally not in low or grassy places. In Jefferson County, also collected at Chatfield. Probably more common than the number of collections would indicate, because many collectors including the author are reluctant to collect cactus because of their rariety.

First collected by Nuttall near the Mandan villages and published in Fraser's (1813) Catalogue. Subject to some confusion about recognition of species because it's form varies widely over a broad distribution, from southern Canada to northern Mexico, it was placed in Escobaria vivipara by Britton & Rose (1913). Since then, it has bounced back and forth between Coryphantha and Escobaria several times. Colorado authors (Ackerfield, 2015; Weber & Wittmann, 2012) have accepted Coryphantha vivipara in the past. Recent phylogenetic studies (Sanchez, et al., 2022) show our plant deeply embedded within Escobaria Britton & Rose, as recognized in our current Flora of Colorado (Ackerfield, 2022 2ed.).

Small Escobaria vivipara in bloom beside Utah Highway 21	Obs. No. 1553, Escobaria vivipara

Opuntia macrorhiza Engelm. “Western Pricklypear”

There are two Opuntias or Pricklypears that are common in Golden s.l. Both are scattered in all the open spaces, and sometimes are found growing together.

“Western Pricklypear” — Opuntia macrorhiza Engelm. — has been found on North and South Table Mountains, Dakota Ridge, Schweich Hill, and the Survey Field. The pricklypear has been found in all the intensely-collected localities in Jefferson County. It is probably more common that the number of collections (n=17) would indicate; collecting these cacti is a difficult and prickly activity. Most of the collections are along the Front Range and foothills with a few collections in the Colorado mountain valleys.

This cactus was first described by George Engelmann (1850) from a collection by F. Lindheimer on the Guadalupe River of west Texas. Some manuals apply a common name of “Twistspine Pricklypear.” I do not perceive the spines to be twisted, at least not in the sense that the awns of some grasses are twisted, and think that Ackerfield's (2015) use of “Western Pricklypear” would be preferred. Observations of O. compressa are assumed to be O. macrorhiza.

Coll. No. 2371, Opuntia macrorhiza	Obs. No. 1540, Opuntia macrorhiza	Coll. No. 1948, Opuntia macrorhiza

Opuntia polyacantha Haw. “Plains Pricklypear”

Like the preceeding, the “Plains Pricklypear” — Opuntia polyacantha Haw. — is found in most localities in Golden s.l. with collections specifically from North and South Table Mountain, Dakota Ridge, Schweich Hill, and Deadman Gulch (Kinney Run). The distribution of Plains Pricklypear in Jefferson County is roughly the same as Western Pricklypear. In Colorado there are many collections from the plains, foothills, and mountain valleys.

First recognized as a species by Thomas Nuttall (1818) in his Genera of North American Plants as Cactus ferox, although that name was not available because it had been previously used by Willdenow (1814). Haworth (1819) provided a valid name, citing both Nuttall's name and a specimen grown in the Physic Garden of Chelsea along the Thames River in London.

Obs. No. 1427, Opuntia polyacantha	Coll. No. 2445, Opuntia polyacantha

There are several other taxa of Opuntia that some think occur along the Front Range, though our current Flora of Colorado (Ackerfield, 2022) and other older floras do not accept them. Chief among them is Opuntia cymochila Engelmann & J. M. Bigelow. This cactus was described as a form of Opuntia rafinesquei by George Engelmann and John M. Bigelow (1856) when describing the cacti from Whipple Expedition of the Pacific Railroad Surveys. O. tortispina was described in the same report. Most current floras treat O. cymochila as a synonym of O. tortispina (Allred, 2012; Pinkava, 2003; POWO, 2023). There are 32 vouchers collected in Colorado determined O. cymochila in the SEINet data base and 25 vouchers of Opuntia collected in Colorado determined O. tortispina.

The iNaturalist app will “recognize” specimens of O. cymochila and O. tortispina. Several iNaturalist curators accept both taxa in Colorado, adding identifications of O. cymochila to observations identified as Opuntia sp., O. macrorhiza, or O. polyacantha. iNaturalist has 669 observations identified O. cymochila, 257 of which are in Research Grade status, and 540 obervations identified O. tortospina, 201 of which are also in Research Grade status (as of 22 Oct 2023).

Being a more or less dedicated Herbarium Junkie, who prefers to work with accepted names, with the objective of a “clean” list of plants in Golden, I am unclear at this time about recognition of O. cymochila and/or O. tortispina in Golden.

Pediocactus simpsonii (Engelm.) Britton & Rose “Mountain Ball Cactus”

Known from North and South Table Mountains, and Dakota Ridge. An iconic, easily recognized cactus found in open, dry places throughout much of Colorado.

The cactus was named for Captain J. H. Simpson who led an expedition to Utah Territory in 1859. Collections were made in Butte Valley and Kobeh Valley of today's Nevada by Henry Engelmann, and named by his brother, George Engelmann (1863). A variety was collected at Mount Vernon, Jefferson County, by Parry, Hall and Harbour, though the variety is not currently accepted because the cactus is highly variable throughout its range.

Pediocactus simpsonii (Nutt.) Haw.

Chamerion angustifolium (L.) Holub. “Fireweed”

There is perhaps one collection of Chamerion angustifolium (L.) Holub. “Fireweed” from Golden s.l., i.e., on Lookout Mountain. Otherwise, the Jefferson County localities are in the interior of the county from Squaw Mountain to Buffalo Peak, although the author collected our plant at Lippincott Ranch (highest Great Plains) in 2021. Most Colorado collections are in the Rocky Mountains on both the east and west slope.

This is a circumpolar species, first published by Linnaeus (1753) as Epilobium angustifolium, placed in Chamerion by Holub (1972), but some of the more recent literature are treating the plant as an Epilobium.

Circaea alpina L. “Small Enchanter's Nightshade”

There are two collections of Circaea alpina L. “Small Enchanter's Nightshade” that may be in Golden s.l., one high in Apex Gulch, and the other only identified as Golden. Most of the collections in Jefferson County are well up into the foothills, though the author has collected it at Lippincott Ranch. Colorado state collections are also in the foothills, mostly on the east slope, with just a few collections on the west slope.

Epilobium L. “Willow-Herb”

Epilobium (from the Greek) Willow-Herb It is the largest in the family and contains the great majority of species of Onagraceae found in the Old World. Most of the species are somewhat mesophytic in habitat preference. In this genus, the mode of vegetative propagation is variable, some species having above-ground stolons. Those of Iraq have below ground level, either turions (fleshy overwintering buds), soboles (pale elongate shoots) or leafy rosettes which are ± erect. The genus name derives from the Greek words "epi" meaning "upon" and "lobos" meaning "lobe", with reference to position of the petals above the ovary.

Epilobium brachycarpum C. Presl “Autumn Willow Herb”

Two collections of Epilobium brachycarpum C. Presl “Autumn Willow Herb” in Golden s.l., both in the vicinity of Heritage Square and Apex Gulch. Jefferson County collections are along the Front Range, including collections by the author at Ranson/Edwards and Lippincott Ranch. Colorado collections are scattered around the state from the Front Range to the west.

Reliquiae Haenkeanae, published by Presl (1830-1835) was based on botanical specimens collected in the Americas by Thaddaeus Haenke.

Epilobium ciliatum Raf. “Fringed Willowherb”

Common in damp areas throughout Golden s.l., sometimes with E. hirsutum, unfortunately. Common in the northern part of Jefferson County, though there are no collections from the southern part. Found throughout the state of Colorado, but sparingly out on the plains.

The name was published by Rafinesque (1808) in a publication — Medical Repository — that I have not been able to find online.

Oenothera L

There are ten species of Oenothera L. known from Golden s.l., nine of which are native. These nine species are represented by 31 collections. Six of the nine native species are represented by one or two collections. This seems a little suspicious to me, that perhaps some of those collections are mis-identified.

The four caespitose or acaulescent Oenothera are:

• O. albicaulis
• O. brachycarpa
• O. caespitosa
• O. howardii

The six caulescent Oenothera are below. Ackerfield (2022) says “stems evidently leafy.”

• O. biennis L.
• O. coronopifolia Torr. & A. Gray
• O. curtiflora W. L. Wagner & Hoch
• O. nuttallii Sweet
• O. suffrutescens (Ser.) W. L. Wagner & Hoch
• O. villosa Thunb.

Oenothera albicaulis Pursh “Whitest Evening Primrose”

Three collections, one on Lookout Mountain, and two on South Table Mountain. All the collections are below the foothills of Jefferson County. At the state level, collections are widely scattered around the state.

The name was first proposed by Nuttall (1813) for a plant he collected on the Missouri, though we now treat this name as invalid because there was no description, or means to distinguish this Oenothera from any other. Pursh (1813) published the name again citing Nuttall's name, and also acknowledgeing a collection by Bradbury.

Oenothera brachycarpa A. Gray “Short-Fruit Evening Primrose”

Oenothera brachycarpa A. Gray “Short-Fruit Evening Primrose” is known from three collections; two historic collections that have very similar handwritten labels, from and a more recent collection on South Table Mountain. Other Jefferson County collections are just along the base of the foothills. Similarly, Colorado state collections are along the base of the foothills in near Boulder and Denver.

Not accepted in Colorado by Weber & Wittmann (2012) or Ackerfield (2015), accepted by Harrington (1964, 2nd ed.).

First described by Gray (1852) from collections by Wright in west Texas.

Oenothera cespitosa Nutt. “Tufted Evening Primrose”

“Tufted Evening Primrose.” — Oenothera cespitosa Nutt. — and two of its varieties have been collected on North and South Table Mountains, and on Lookout Mountain. There are only a few (25) collections of O. cespitosa in Jefferson County, and none at the intensely-collected sites of Rocky Flats or Chatfield. The species seems to be found primarily in the American Cordillera and western Great Plains.

The caespitose Oenothera at Rocky Flats have been O. howardii and O. flava. The latter is not known from Golden s.l. At Chatfield O. albicaulis, O. brachycarpa, and O. howardii have been collected.

First collected by Lewis & Clark in 1806 at Falls of the Missouri. However, first described by Nuttall in Fraser's (1813) Catalogue. The location of the collections is not identified in that publication. However, Nuttall (1818) in his Gen. Am. gives the location as the banks of the Missouri River from the White River to Fort Mandan. This is one of Nuttall's names that have stood the test of time.

Coll. No. 1407, Oenothera cespitosa var. macroglottis

Oenothera coronopifolia Torr. & A. Gray “Crownleaf Evening Primrose”

There is one collection of Oenothera coronopifolia Torr. & A. Gray “Crownleaf Evening Primrose” in Golden s.l., made more than 100 years ago at the base of Lookout Mountain. This would be in the present-day Survey Field. The handwriting on this collection is very similar to the two historic collections of O. brachycarpa, above. Other collections in Jefferson County are in the foothills, as far south as the Buffalo Creek Recreation Area. Colorado state collections are from around the state except for the higher ranges in the north-central section of the state. The author has collected our plant at Salt Creek, Park County, Colorado.

Collected by Edwin James, MD, probably near the forks of the Platte River, and described by Torrey & Gray (1840) in their Flora of North America.

Oenothera curtiflora W.L. Wagner & Hoch “Velvet Butterfly-Weed”

Collected on North and South Table Mountains, and Heritage Square, Oenothera curtiflora W.L. Wagner & Hoch “Velvet Butterfly-Weed” is found in grasslands, fields, and disturbed areas. In Jefferson County, it is found at the base of the foothills and out on the plains. Colorado collections are mostly on the plains and in the valleys of the west slope. It is native to the central part of North America.

There is an error in Ackerfield (2015) Flora of Colorado in that our plant is named O. curtifolia whereas the correct name is O. curtiflora.

Notwithstanding some controversy, the first name applied to this plant was Gaura mollis James. Goodman & Lawson (1995) explain that James published his name a few months before Gaura mollis HBK. I assume that Oenothera mollis was not available because of Oenothera mollissima L.

Oenothera howardii (A. Nels.) W. L. Wagner “Howard's Evening Primrose”

Seven collections in Golden s.l., mostly between the Survey Field and South Table Mountain. Jefferson County collections are out on the plains and up against the foothills as far south as Chatfield. Colorado state collections are along the Front Range, and then out on the southeast plains.

The name was first used by Jones (1893) though in an invalid way. This was fixed by Nelson (1902) as Lavauxia howardii. Placed back in Oenothera by Wagner (1983).

Oenothera nuttallii Sweet “Nuttall's Evening Primrose”

There is a single collection of Oenothera nuttallii Sweet “Nuttall's Evening Primrose” that may be in Golden s.l. It was made in 1960 “Just east of Golden along the Coors Brewery Road.” There is one other collection in Jefferson County, that of well-known California botanist Philip A. Munz, made 8 miles west of Morrison. Colorado collections are concentrated along the Front Range, North Park, with a few out on the plains.

First intended to be O. albicaulis Nuttall (1813), though this is considered nom. inval.. Then, Pursh (1814) published O. albicaulis for a different plant, and listed Nuttall's name in error as a synonym. Sweet (1830) corrected this and published the plant as O. nuttallii.

Oenothera suffrutescens (Ser.) W. L. Wagner & Hoch “Linda Tarde”

Oenothera suffrutescens (Ser.) W. L. Wagner & Hoch “Linda Tarde” is one of those plants that does not form large colonies, but is found most everywhere; from Dakota Ridge in the north to Tin Cup Ridge in the south,

Oenothera villosa Thunb. “Hairy Evening Primrose”

Collected in Apex Gulch and on South Table Mountain, Oenothera villosa Thunb. “Hairy Evening Primrose” is not common in Golden s.l. The author has not seen it in Golden, though I have collected it at three widely separated places at Ranson/Edwards. Jefferson County collections are widely distributed, on the plains, at the base of the Front Range, and the interior of the county, such as the Buffalo Creek Recreation Area. It is found in nearly every county of Colorado.

The plant was described by Thunberg (1794) from Cape of Good Hope, Africa, where it was introduced, though its native range is Subarctic America to U.S.A.

Aralia nudicaulis L. “Wild Sarsaparilla”

Two collections in Golden s.l., one in Vidler's Gulch, the other in a generic Lookout Mountain location. Found in lower elevations of the Front Range of Jefferson County, and the most of Colorado, and not out on the plains.

Aletes acaulis (Torr.) J.M. Coult. & Rose “Stemless Indian Parsley”

Found along the cliffs of North and South Table Mountains, and steep rocky slopes above Welch Ditch. In Jefferson County, from Bear Creek North, as are most collections in Colorado, except a scattered few on cliffs south and west of Denver.

Finding a appropriate name for this plant was quite a challenge and, at one time, it was known simultaneously by names in three different genera, all published by A. Gray. For this reason Coulter & Rose (1888) published a new genus just for this species.

Unfortunately, recent phylogenetic work (Sun & Downie, 2010) suggests that Aletes and associated taxa of Lomatium, Cymopteris, and Musineon are in quite a muddle, and we may soon see a reorganization.

Coll. No. 1321, Aletes acaulis

Harbouria trachypleura (A. Gray) J.M. Coult. & Rose “Whiskbroom Parsley”

Common in Golden s.l. having been collected on North Table Mountain, through Kinney Run, to Apex Park and Tin Cup Ridge. Curiously, it has not been collected in South Table Mountain. There are currently collections from most areas of Jefferson County. The plant is found along the Front Range from Colorado Springs north with a few scattered collections to the south.

Ligusticum porteri J.M. Coult. & Rose “Porter's Licorice-Root”

There are records of two collections of “Porter's Licorice-Root” — Ligusticum porteri J.M. Coult. & Rose — in the Golden area. Presumably these were from Lookout Mountain, although all location information about this species is redacted. While reasonably widely distributed, the species is threatened by wild-collecting. It is the roots, known as “osha,” that are used for medicinal purposes and so commercial harvests are very likely to be harmful to local populations. Only Ligusticum porteri is deemed “true” osha. The root is considered an immune booster and aid for coughs, pneumonia, colds, bronchitis, and the flu. It’s also used to relieve indigestion, lung diseases, body aches, and sore throats.

Not rated for rariety by CNHP. Rated as S2 – Imperiled, by NatureServe. Global status G3 – Vulnerable.

Lomatium orientale J.M. Coult. & Rose “Salt-and-Pepper”

The common name I started with for Lomatium orientale J.M. Coult. & Rose was “Northern Idaho Biscuitroot.” Turns out, though, that the plant doesn’t grow in Northern Idaho, and by its scientific name might be called “Western Biscuitroot” However, out current manual of Colorado flora (Ackerfield, 2015) gives a common name of “Salt-and-Pepper,” an allusion to the dappled appearance of the inflorescence.

This is a very common early perennial in Golden s.l. that has been collected pretty much everywhere from Dakota Ridge in the north to Tin Cup Ridge in the south.

Musineon divaricatum (Pursh) Raf. “Leafy Wildparsley”

Much less common than some of the preceeding Carrot family representatives, “Leafy Wildparsley” — Musineon divaricatum (Pursh) Raf. — has been collected at only two sites in Golden s.l.: Deadman Gulch and South Table Mountain. In Jefferson County it is found only at the base of the Front Range and out on what used to be the plains. The state distribution is similar, though the distribution on the plains is spotty.

First recognized by Pursh (1814) from a collection by Bradbury “… in upper Louisiana.”

Cornus sericea L. “Creek Dogwood”

There are two collections of Creek Dogwood in Golden s.l., one on Lookout Mountain, and the other on the north side of South Table Mountain. It probably is also on the north side of North Table Mountain, and in the mouth of Clear Creek Canyon.

Described by Linnaeus (1771) as being native to North America, it has an amazing 71 synonyms (Kew, 2022). C. sericea itself is sometimes treated as a synonym of C. alba. Some cultivars are planted for their bright red stems in winter and have a common name of “red-osier dogwood.”

Arctostaphylos uva-ursi (L.) Sprengel “Bearberry”

A circum-polar plant, Arctostaphylos uva-ursi (L.) Sprengel “Bearberry” has been collected on Lookout Mountain and Tin Cup Ridge. The main part of Golden s.l. is a little lower than its usual range. The author grows it in town, though in high shade beneath a crabapple tree.

Bearberry is more common in the interior of Jefferson County. For example the author has collected it on the slopes of Little Scraggy Peak (Buffalo Creek Recreation Area) and at Goose Creek. In Colorado, it is a common forest groundcover and is found throughout the mountain ranges of Colorado.

Orthilia secunda (L.) House “Sidebells Wintergreen”

A common plant of moist coniferous forests, there is one or maybe two collections of Orthilia secunda (L.) House “Sidebells Wintergreen” in the portion of Golden s.l. on Lookout Mountain.

The plant was first described as Pyrola secundus by Linnaeus (1753) then separated into Orthilia by House (1921) as a nomenclatural change without explanation.

The Colorado distribution is mountainous areas of Colorado.

Pyrola asarifolia Michx. “Liverleaf Wintergreen”

Common along streambanks and in moist, shaded forests, there are three collections of Pyrola asarifolia Michx. “Liverleaf Wintergreen” on Lookout Mountain and may therefore be counted in the flora of Golden s.l. The most recent of the three collections was made 100 years ago.

The plant was firest described by Michaux (1803).

Androsace occidentalis Pursh “Western Rockjasmine”

Found on North and South Table Mountains, and the Survey Field. Jefferson County collections are along the base of the Front Range, with one collection in the foothills. From a state perspective, mostly in the interior valleys and along the Front Range.

Described by Pursh (1814) from a collection by Nuttall on the banks of the Missouri River.

Androsace septentrionalis L. “Pygmyflower Rockjasmine”

One collection on Lookout Mountain that may be in Golden s.l.. Found mostly in the foothills of Jefferson County, including collections by the author in Buffalo Creek Recreation Area. There are numerous Colorado collections, nearly all in the mountains from the Front Range to the west.

According to Linnaeus (1753), “She lives in the sunny pebbly Alps of Lapland, Russia.” Plants of the World (Kew, 2022) states that its native range is temperate northern hemisphere.

Dodecatheon pulchellum (Raf.) Merr. “Beautiful Shootingstar”

Several collections around Golden s.l. usually in steep wet gulches or marshy areas. Jefferson County collections are in the foothills of the county or in gulches or along streams at the base of the Front Range. In addition to Apex Park, the author has collected our plant in the mouth of Clear Creek Canyon, in Magpie Gulch, and at Morrison Creek in the Buffalo Creek Recreation Area. Similarly, state of Colorado collections are found in meadows, moist places, and spruce or aspen forests.

The naming of our plant went through several gyrations, with characters such as Drummond, Michaux, Hooker, Rafinesque, Greene, and Rydberg involved, ending with Merrill's (1948) Nomenclatural Notes on Rafinesque's Published Papers, 1804-1840.

Coll. No. 2927, Dodecatheon pulchellum in Magpie Gulch.

Lysimachia ciliata L. “Fringed Loosestrife”

One collection definitely in Golden s.l., i.e., Apex Gulch, and another on Lookout Mountain that may be in Golden. Collected by the author twice at Ranson/Edwards, it is common at Rocky Flats, and just barely up into the foothills of Jefferson County. Found mostly along the Front Range of Colorado with a kind of odd smattering of locations in the interior of the state.

Described by Linnaeus (1753) from locations in Virginia and Canada.

Eustoma grandiflorum (Raf.) Shinners “Showy Prairie Gentian”

Known from Golden s.l. from a single collection made in 1905 on Lookout Mountain above Golden, there are quite a number of collections from Wheat Ridge and Arvada. Most Colorado collections are found from the base of the Front Range out onto the plains.

Some sources, e.g., POWO (Kew, 2022) treat E. grandiflorum as a synonym of E. russellianum (Hook.) G. Don, the question appearing to one of priority of Hooker's name over Rafinesque's name.

Frasera speciosa Griseb. “Elkweed”

Frasera speciosa Griseb. “Elkweed” has been observed in the lower canyons of Windy Saddle Park, but not collected.

Other Jefferson County collections have been made at Rocky Flats, Ranson/Edwards, and Lippincott Ranch, in addition to a couple of collections in the foothills.

Most Colorado collections are in the mountains west of the Front Range.

Apocynum cannabinum L. “Indian Hemp”

One collection from South Table Mountain, and a report from North Table Mountain. The name is a Linnaean (1753) name, who cited habitat in Canada and Virginia.

Apocynum ×floribundum Greene “Dogbane”

Every “Dogbane” that I have collected in Golden s.l. and along the Front Range has turned out to be the hybrid — Apocynum ×floribundum Greene. I'm not sure whether that says more about the plants or my identification skills. Regardless, my collection in Golden s.l. was on North Table Mountain, whereas the next, A. cannabinum has been reported for North Table Mountain, and collected on South Table Mountain.

The plant was first recognized by Greene (1893) from specimens in the southern Sierra Nevada of Kern County, California. It has been described as a variety of A. cannabinum by Jepson (1939). and as a variety of A. medium by Munz (1965). The Jepson Manual of California (Baldwin, 2012) treats it as a synonym of A. androsaemifolium.

Asclepias incarnata L. “Swamp Milkweed”

Asclepias pumila (A. Gray) Vail “Plains Milkweed”

Collected on North and South Table Mountains, the “Plains Milkweed” — Asclepias pumila (A. Gray) Vail — is very small and unassuming, leading me to suggest it is often overlooked. For example, I know of some rescue collecting done at the corner of US Highway 6 and Heritage Road that resulted in a large clump being moved to a private garden.

First described as a depauperate or dwarf form of A. verticillata L. by Gray (1876). This makes a lot of sense because the leaves are whorled, a fairly uncommon character of milkweeds. Britton & Brown (1898) elevated variety pumila to the rank of species without comment.

Asclepias speciosa Torr. “Showy Milkweed”

Tall, large-flowered, and with a distinctive seed pod covered with tubercules, the “Showy Milkweed” — Asclepias speciosa Torr. — is very widely distributed in Golden s.l., Jefferson County and Colorado.

First described by John Torrey (1828) from a collection by Edwin James, MD. The type was collected on June 14, 1820, as the Stephen H. Long expedition traveled south from the Loup River to the Platte through Merrick County, Nebraska (Goodman and Lawson, 1995, p. 130-131).

Seed pod of Asclepias speciosa	Seed of Asclepias speciosa

Asclepias stenophylla A. Gray “Narrow-leaved Milkweed”

There is one old collection of Asclepias stenophylla A. Gray “Narrow-leaved Milkweed” that may have been in or near Golden s.l. This was an Edward L. Greene collection in 1870, his first year of collecting in Colorado. Given this plant's normal distribution in mixed-grass prairie, it has probably been extirpated. There are two other collections in Jefferson County, one at Rocky Flats, and the other by the author at Ranson/Edwards by the author. Of the Colorado collections without redacted location data, most are along the Front Range, from Denver to the north. USDA describes the natural range as Midwest and Great Plains, from Illinois to Minnesota to Montana, south to Louisiana and Texas.

Our plant is generally rated by Colorado Natural Heritage Program as S2 — “Imperiled” at the state level, but as G4G5 — “Apparently Secure” at the global level.

First collected in Arkansas between Fort Smith and the Red River by Thomas Nuttall (1834b) who published it as Polyotus angustifolius. Decaisne in DeCandolle (1844) placed our plant in Acerates as A. angustifolia Decne. Gray (1876) moved it to Asclepias.

Coll. No. 2739, Asclepias stenophylla

Asclepias viridiflora Raf. “Green Comet Milkweed”

Less common than the preceding, the “Green Comet Milkweed” — Asclepias viridiflora Raf. — has been found on North and South Table Mountains, and in Apex Park.

There are two similarly named milkweeds, e.g., A. viridis and A. viridula, but those two species are not known from Colorado.

A. viridiflora has been seen in flower in Apex about the 10th of June, and in fruit on North Table Mountain near the end of July.

Fruit of Asclepias definitely, maybe A. viridiflora

Evolvulus nuttallianus Roem. & Schult. “Shaggy Dwarf Morning Glory”

In the Morning-Glory family (Convolvulaceae) most everyone recognizes Field Bindweed (Convolvulus arvensis) a ubiquitous noxious weed, and a plague on every well-tended garden.

It may come as a surprise, then, that there is also a small native perennial morning-glory that is common in sandy places on the plains and found occasionally in the lower foothills. It is the “Shaggy Dwarf Morning Glory” (Evolvulus nuttallianus). Found first by Thomas Nuttall in 1811 on the banks of the Missouri River, it was first named E. argenteus by Frederick Pursh (1814) in his North American Flora. However, the name was previously published by Robert Brown (1810) in his natural history of Australia and Tasmania, then called New Holland and Van Dieman's Land, respectively. Therefore, Pursh's name was illegitimate. Roemer & Schultes (1820) rectified this when they published volume 6 of the 16th edition of Linneaus' Systema Vegetabilium, by applying a new name of E. nuttalianus after, of course, the name of the original collector, Thomas Nuttall.

The first collection in Colorado was made by George Vasey of Powells Colorado Exploring Expedition of 1868. There are vouchers at PRBU, NY, and SJNM (SEINet, 2020). It is not known where in Colorado the collection was made.

In Jefferson County, there are seven collections, one of which is mine from the Schweich Hill. Loraine Yeatts collected the plant on South Table Mountain in 1983. Four collections were made at Rocky Flats, probably the best studied piece of ground in Jefferson County, and there is one collection from Chatfield.

Flower of Coll. No. 2319, Evolvulus nuttallianus	Coll. No. 2319, Evolvulus nuttallianus

Aliciella pinnatifida (Nutt. ex A.Gray) J.M.Porter “Sticky Gilia”

Collections from North Table Mountain and Heritage Square. The lack of collections, especially from South Table Mountain, is surprising. Tends to be found more in the foothills of Jefferson County than out on the Great Plains, although it is found on the plains in counties north and south of Jefferson County.

First described as Gilia pinnatifida by Asa Gray (1870) in his Revision of the Polemoniaceae (Phlox family) from a Nuttall collection in Gray's herbarium. There must have been some description written by Nuttall for Gray to give credit to Nuttall. The oldest known extant collection was by Frémont 1842 from the Torrey Herbarium (NY3261962). The oldest collection in the Gray Herbarium is by Fendler 16 June 1847 (GH1154924). This collection was designated as a lectotype by Porter 15 January 2002. Moved to a recircumscribed Aliciella by Porter (1998) because molecular data showed the group was more closely allied to Loeselia and Ipomopsis than to Gilia. Aliciella, by the way, is named for Colorado's Alice Eastwood.

Collomia linearis Nutt. “Tiny Trumpet”

Two collections in Golden s.l., both from approximately the same area: Apex Gulch, west southwest of the Magic Mountain archeological dig. Also found at Rocky Flats, Chatfield, and various places in the Jefferson County foothills. Throughout the Colorado Rocky Mountains, but only out on the Great Plains on the Palmer Divide.

Nuttall (1818) proposed both the genus and specific name, and they have withstood the test of time.

Gilia ophthalmoides Brand “Pinyon Gilia”

There are four collections of various Gilias that were collected in Golden s.l. 60 to 100 years ago, plus one more collection made in 2023 by Cindy Trujillo and me on the northwest edge of Golden. The various vouchers are annotated a mix of G. inconspicua, G. opthalmoides, and G. sinuata. Ackerfield (2015) treats G. inconspicua as a synonym of G. opthalmoides.

Three collections are possibly G. ophthalmoides, one each by Marcus E. Jones (1878), Ira W. Clokey (1921), and Ellsworth Bethel (1921). All three simply give the location as “Golden.” My collection with Cindy Trujillo was made on the ridge between Magpie Gulch and Nightbird Gulch just outside city limits. Other Jefferson County collections were made at Rocky Flats and around Morrison. So the locations could all be characterized as along the base of the Front Range. At the state level, there are other collections along the Front Range, but our plant is more common on the west slope.

G. ophthalmoides was described by A. Brand in Engler's (1907) Das Pflanzenreich from a collection by Carl A. Purpus made in washes at Gold Mountain, 1898. An image of this voucher is available online.

G. ophthalmoides is another western plant that is found from the Front Range on the east side of the Rocky Mountains, then west to the east side of the Sierra Nevada.

Distribution of Gilia ophthalmoides in western North America.	Coll. No. 2924, Gilia ophthalmoides	Coll. No. 283, Gilia ophthalmoides

Gilia sinuata Benth. “Rosy Gilia”

There is only one collection made in Golden s.l. that is currently determined Gilia sinuata Benth. “Rosy Gilia.” Not surprisingly, it was made by Ernest H. Brunquist at the Peabody Museum archeological dig. Jefferson County collections are along the base of the Front Range, at Morrison and Kassler, in addition to Golden. Colorado state collections are on the west slope, in addtion to those in Jefferson County. Its native range is British Columbia (type, extinct) to New Mexico and Mexico (Baja California Norte, Sonora).

Published by Bentham in DeCandolle (1845) from a manuscript by Douglas. The type locality is the Okanagon Valley, where our plant is thought to now be extinct.

Ipomopsis aggregata (Pursh) V. E. Grant ssp. aggregata

Ipomopsis aggregata (Pursh) V. E. Grant ssp. candida (Rydb.) V. E. Grant & A. D. Grant “Scarlet Gilia”

All of the collections of Ipomopsis aggregata made in Golden s.l. — so far! — have been ssp. candida (Rydb.) V. E. Grant & A. D. Grant “Scarlet Gilia.” There are five collections and one observation from North and South Table Mountain, and Lookout Mountain, plus one collection from the generic location of Golden. I also include a collection from the unfortunate location of Jackson Gulch, now occupied by the Martin-Marietta quarry at the south end of Golden. Collections along the base of the Front Range of Jefferson County are in the minority, with most collections of this subspecies in the lower foothills. Collections of subspecies collina are distributed a little farther south, such as the Buffalo Creek Recreation Area.

The species was first described by Pursh (1814) from a Lewis & Clark collection in Idaho. Rydberg (1901) described the subspecies at the rank of species from a collection made near La Veta, Animas County, Colorado. Grant (1956) reduced our plant to rank of subspecies under Ipomopsis aggregata without comment.

Coll. No. 1228, Ipomopsis aggregata ssp. candida	Coll. No. 2565, Ipomopsis aggregata var. candida

Ipomopsis spicata (Nutt.) V.E. Grant “Spiked Ipomopsis”

Not often collected around Golden s.l., those collections that have location data are from South Table Mountain and above Deadman Gulch at the edge of the survey field. There are two historic collections that imply they were made at the base of Lookout Mountain, which probably means the Survey Field or Beverly Heights.

A little more broadly, there are collections in Jefferson County from the extensively-collected localities of Rocky Flats and Chatfield.

First described as Gilia spicata by Nuttall (1848b) from a collection on the Platte River at Scott's Bluff, Nebraska.