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Detailed Area Plant List for Welch Ditch (Open Space), Jefferson County County, United States.
Edited by Tom Schweich
This list is assembled from personal collections, herbarium vouchers, and published lists that were available at the time this list was prepared. There may be additional species of plants in this area that were unknown or undocumented at the time this list was prepared. For California, much of the data is provided by the participants of the Consortium of California Herbaria as indicated by a single dagger “†.” Their web site is at: (http://ucjeps.berkeley.edu/consortium/). For Colorado, much of the data is provided by the Southwest Environmental Information Network as indicated by a double dagger “‡,” which web site is found at (http://swbiodiversity.org). See their respective websites for copyright information and recommended citation formats.
For a complete list of Locations included in this Area List, see the Locations Included section, below. For a check list, please see: Check List for Welch Ditch (Open Space), Jefferson County County, United States.
Cupressaceae
Juniperus . Horticultural Juniper. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4718. 4/25/2026. .
Pinaceae
Picea pungens Engelm. Colorado Blue Spruce. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4726.
4/25/2026.
.
.
 Obs. No. 3812, Picea pungens. |
 Spruce tree at 900 5th Street. |
 Spruce tree at 900 5th Street. |
Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco. (Syn: Pseudotsuga menziesii (Mirb.) Franco var. glauca (Mayr) Franco ) Douglas-fir. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4725.
4/25/2026.
.
Anacardiaceae
Rhus trilobata Nutt. var. trilobata. (Syn: Rhus aromatica Aiton var. trilobata (Nutt.) A. Gray ex S. Watson ) Skunkbush Sumac. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4705.
4/25/2026.
.
Apiaceae
Conium maculatum L. Common Poison Hemlock. Weed: CO DofA, List: C. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4714.
4/25/2026.
.
 Coll. No. 1436, Conium maculatum |
Apocynaceae
Vinca minor L. Lesser Periwinkle. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4728. 4/25/2026. .
Asteraceae
Arctium minus Bernh. Lesser Burdock. Weed: CO DofA, List: C. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4695.
4/25/2026.
.
.
 Obs. No. 3819, Arctium minus. |
 Coll. No. 2425, Arctium minus. |
 Coll. No. 3302, Arctium minus. |
Cirsium arvense (L.) Scop. (Syn: Breea arvensis (L.) Lessing ) Canada Thistle. Weed: CO DofA, List: B. CalPhotos. Jepson eFlora. SEINet Taxon.
Annual, to 70 cm., tap-rooted; Leaves, cauline, alternate, sessile but not obviously decurrent, 85 mm. × 20 mm. wide, margin sinuate, spiny, adaxial thinly tomentose, abaxial tomentose; Inflorescence, panicle(?); Heads, many, 30±, 15 mm. × 8 mm. dia., disk flowers only, dioecious, staminate heads, pappus < corolla, pistillate heads, pappus > corolla; Phyllaries, many (6-7) series, outer 3 mm. × 1.5 mm. wide, inner 15 mm. × 1 mm. wide, dark dorsal ridge, tips, spinulose, reflexed; Receptacle, soft bristles, 10 mm.; Pappus, plumose bristles (Described from Coll. No. 1512, 24 July 2016).
- Welch Ditch (Open Space),
4717.
4/25/2026.
4723.
4/25/2026.
.
.
 Coll. No. 1200, Cirsium arvense |
 Coll. No. 3210, Cirsium arvense. |
 Coll. No. 1512, Cirsium arvense |
 Coll. No. 2773, Cirsium arvense |
Ericameria nauseosa (Pall. ex Pursh) G.L.Nesom & G.I.Baird var. graveolens (Nutt.) Reveal & Schuyler. (Syn: E. n. (Pall. ex Pursh) G.L.Nesom & G.I.Baird var. glabrata (Gray) G.L. Nesom & Baird ) Goldy-Locks. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4696.
4/25/2026.
.
.
Helianthus pumilus Nutt. Little Sunflower. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial herb, to 40 cm.; Leaves, cauline, alternate, occasionally opposite, then bases conjoined, simple, petiole 7-10 mm. + blade 55-86 mm. × 22-30 mm. wide, lanceolate, flat (not folded), margin, entire to lightly toothed, adaxial, pustular strigose, hairs multicellular, crosswalls clear, abaxial, glandular and strigose; Inflorescence, heads single to few on leafy stems, peduncles to 8-10 cm., hairy, glandular; Involucre, 9 mm. × 16 mm. wide; Phyllaries in 2+ series, similar, 6-10 mm. × 2.0-3.5(4) mm. wide, greene erect, ovate, strigose abaxially, margins ciliate, tip acuminate, not as “stiff” or “tough” as those of Coll. No. 1199; Receptacle, slightly convex, paleate; Disk, 17 mm. wide; Palea, 9 mm., tip, glandular, hairy distally; Flowers, 2 kinds; Ray flowers, sterile, #10-12, corolla, 17-25 mm. × (4)6-9 mm. wide, yellow; Disk flowers, corolla, 4-6 mm., yellow, lobes, #5, 1 mm., yellow, anther appendages reddish-brown; Pappus of few long (2.5-4 mm.) aristate scales; Cypsela, 3.5 mm. × 1.4 mm. wide, quadrangular,not laterally compressed black. Described from Coll. No. 1210, 1426, and 1704.
- Welch Ditch (Open Space),
4700.
4/25/2026.
.
.
 Coll. No. 1704, Helianthus pumilus |
 Coll. No. 1426, Helianthus pumilis |
Heterotheca villosa (Pursh) Shinners. (Syn: H. v. (Pursh) Shinners var. nana (A. Gray) Semple , H. v. (Pursh) Shinners var. villosa ) Hairy False Goldenaster. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial herb, to 50 cm.; Leaves, cauline alternate, entire, 1-veined, distal perpendicular to stems, hairs > glands; Heads solitary, with both ray and disk flowers; Phyllaries in 2+ series, unequal, to 7 mm.; Rays, 9 mm.; Pappus double, outer narrow scales ≤ 1 mm. (easier to see on mature fruit), inner bristles, 6.5 mm., white; Fruit, disk 3 mm., hairy.
- Welch Ditch (Open Space),
4701.
4/25/2026.
.
.
Taraxacum officinale F. H. Wigg. (Syn: T. laevigatum (Willd.) DC. ) Common Dandelion. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4681.
4/25/2026.
.
.
Tragopogon dubius Scop. (Syn: Tragopogon dubius Scop. ssp. major (Jacq.) Vollman ) Yellow Salsify. CalPhotos. Jepson eFlora. SEINet Taxon.
Peduncle inflated distally, flowers yellow, phyllaries in 1 overlapping series, ligules 3-5 mm. shorter than phyllaries.
- Welch Ditch (Open Space),
4709.
4/25/2026.
.
 Coll. No. 1115, Tragopogon dubius |
Berberidaceae
Berberis aquifolium Pursh. Holly-leaf Oregon-Grape. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4738. 4/25/2026. .
Boraginaceae
Cynoglossum officinale L. Gypsyflower. Weed: CO DofA, List: B. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4685.
4/25/2026.
4736.
4/25/2026.
.
Brassicaceae
Alyssum simplex Rudolphi. (Syn: A. campestre (L.) L. var. simplex (Rudolphi) Willd. , A. minus Rothm. , A. parviflorum Fisch. ex M.Bieb. ) European Madwort. CalPhotos. Jepson eFlora. SEINet Taxon.
Annual, tap-rooted, to 12-30 cm., stellate hairy throughout (typically doubly branched and 8-pointed); Stem branched at base, ascending; Leaves basal, withered at flowering, appear compound, cauline, alternate, 14-28 mm. × 3.5-5.0 mm., oblanceolate, margin entire, tip acute, sessile or vaguely short-petioled; Inflorescence not bracted; Pedicels, in fruit, 4.5 mm.; Sepals, 4, 2 mm. × 0.7 mm. wide, deciduous in fruit; Petals 2.9-3.0 mm., yellow fading white,clawed, entire to tip slightly notched; Stamens, 2.5-2.6 mm.; Filaments, 2.3 mm., winged proximal 1.5-1.8 mm., not toothed; Style persistent, 1.3 mm., few hairs at base; Fruit round, 3.5-5.0 mm. × 5.6 mm. wide, margin entire, compressed parallel to the replum, hairy, hairs thinning as fruit matures; Ovules, 4 (most keys and descriptions say 2 when they give a specific number, but the genus is described as having 1-2[4] ovules). (Described from Clyde Golden, 25 Jun 2011, Coll. No. 1090, 30 Apr 2015, and Coll. No. 1367, 24 May 2016).
- Welch Ditch (Open Space),
4699.
4/25/2026.
.
.
 Alyssum simplex |
 Alyssum simplex |
 Fruit of Coll. No. 1090, Alyssum simplex |
 Coll. No. 1090, Alyssum simplex |
 Coll. No. 1367, Alyssum simplex |
Chorispora tenella (Pall.) DC. Crossflower. CalPhotos. Jepson eFlora. SEINet Taxon.
Annual, hairs 0, sparsely stalked-gland-dotted; Leaves basal, withered at flowering, cauline simple, not basally lobed or clasping; Flowers radial; Corolla purple; Stamens 6; Ovary linear when young; Fruit linear, bilateral, to 4 cm, seed in proximal 2.5 cm., tip pointed; Seeds in two rows, brown, 1 mm (Described from Coll. No. 301, 5 Nov 2012).
- Welch Ditch (Open Space),
4732.
4/25/2026.
.
.
Hesperis matronalis L. Dame's Rocket. Weed: CO DofA, List: B. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial herb, to 50 cm., hairs, forked on stem, leaf, and sepal, but not fruit; Leaves, basal, withered at flowering, cauline, petiole 3-5 mm. + blade 100 mm. × 35 mm. wide, lanceolate, margin, small-toothed; Inflorescence, raceme; Sepals, #4, 5-6 mm., green, margins purple; Petals, #4, 13 mm. × 4 mm. wide, clawed, purple; Fruit, silique, 40 mm. × 0.6 mm. wide; Seed, 1.7 mm., brown, glabrous (Described from Coll. No. 1441, 15 June 2016).
- Welch Ditch (Open Space),
4740.
4/25/2026.
.
.
 Hesperis matronalis in the ditch. |
 What the well-dressed botanist wears while chasing noxious weeds in the grass. |
 Coll. No. 1441, Hesperis matronalis |
 Coll. No. 2808, Hesperis matronalis |
Thlaspi arvense L. Field Penny Cress. CalPhotos. Jepson eFlora. SEINet Taxon.
Annual, tap-rooted, to 50 cm., generally glabrous throughout; Stem, single, or few-branched proximally; Leaves, basal and cauline, basal, withered at flowering, cauline, sessile, auriculate, oblong, 30 mm. × 5-9 mm. wide, reduced distally, dentate; Inflorescence, raceme; Sepals, 2 mm. × 1 mm. wide, ovate; Petals, 3-3.5 mm. × 1 mm. wide, spoon-shaped, margin entire, white; Stamens, 2 mm.; Anthers, 0.5 mm.; Fruit, pedicels 10-15 mm., ascending to spreading, glabrous, fruit obovate, 10 mm. × 8 mm., wide, margin winged, tip notched 1 mm.; Ovules, biseriate, #many (Described from Coll. No. 1324, 4 May 2016).
- Welch Ditch (Open Space),
4684.
4/25/2026.
.
 Brassicaceae Thlaspi arvense |
 Habitat of Coll. No. 1365, Thlaspi arvense |
 Coll. No. 1365, Thlaspi arvense |
 Coarsely dentate leaves of Coll. No. 1820, Thlaspi arvense |
Cactaceae
Opuntia macrorhiza Engelm. Western Pricklypear. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial cactus, not distinctly mat-forming; Stem, segments, 90 mm. × 60 mm. wide, flattened, bluish-green, areoles, #5-6 per diagonal row, spaced 8-14 mm., proximal, glochids only, distal, glochids and spines, spines, #2, #1, 28 mm., erect, brown to tan at tip, #1, 12 mm., recumbent, nearly white; Flowers, petals, 36 mm. × 22 mm. wide, wedge-shaped, color yellow; Stamens, many, 18 mm., yellow; Style, 20-24 mm., stout; Stigma, lobes, #6-8, 3 mm.; Fruit, 38 mm. × 17 mm. wide, narrow at base, fleshy, green, areoles, mix of glochids and short spines. (Described from Coll. No. 1948, 15 June 2018.)
- Welch Ditch (Open Space),
4704.
4/25/2026.
.
 Coll. No. 2371, Opuntia macrorhiza |
 Opuntia macrorhiza on Schweich Hill. |
 Obs. No. 1540, Opuntia macrorhiza |
 Coll. No. 1948, Opuntia macrorhiza |
Campanulaceae
Campanula rapunculoides L. Rampion Bellflower. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4694.
4/25/2026.
.
 Roots of Campanula rapunculoides |
 Coll. No. 3484, Campanula rapunculoides. |
 Coll. No. 3484, Campanula rapunculoides. |
Caprifoliaceae
Lonicera tatarica L. Tatarian Honeysuckle. CalPhotos. Jepson eFlora. SEINet Taxon.
Shrub to small tree, 2 m.; Leaves, opposite, 24 mm. × 17 mm. wide, simple, entire, petiole, 1.5 mm.; Peduncle, 10-13 mm.; Flowers, in pairs, subtended by bracts, bisexual; Bracts, small, at base of calyx; Calyx, tube 2.0 mm. + lobes 0.5-1.0 mm.; Corolla, tube 12.5 mm. + lobes 12 mm., pink, hairy inside; Ovary, inferior; Stamens, #5, exserted, versatile; Style, #1, exserted, hairy; Stigma, capitate. Disturbed places, native to Siberia, sporadic escapee from cultivation, berries possibly toxic. (Described from Coll. No. 1591, 2 May 2017.)
- Welch Ditch (Open Space),
4687.
4/25/2026.
.
.
 Coll. No. 1591, Lonicera tatarica |
 Coll. No. 2501, Lonicera tatarica |
 Coll. No. 3017, Lonicera tatarica. |
 Coll. No. 1591, Lonicera tatarica |
 Coll. No. 1705, Lonicera tatarica |
Symphoricarpos occidentalis Hook. Western Snowberry. CalPhotos. Jepson eFlora. SEINet Taxon.
Woody perennial to 50 cm., forming dense colonies in moist open swales, [spreading by long sparsely-branched rhizomes,] Twigs without lenticels, minutely hairy when young; Leaves opposite, ovate, to 7 cm. × 5 cm. wide, reduced above, thick, approaching leathery, pinnately veined, upper surface glabrous, lower few short white hairs, margin slightly wavy, slightly rolled under, sparsely curved hairy; Petioles to 7 mm.; Inflorescence axillary (and terminal?); Floral bracts triangular, 3 mm.; Flowers in dense axillary clusters, bisexual, ±radial, possibly slightly bilateral, 2 or more whorls; Corolla fused at base, tube 2-3 mm., throat with recurved hairs, lobes 5, 2.0-3.5 mm, slightly longer than tube, hairy within at level of stamen insertion, white with magenta mottling; Stamens 5, alternate, exserted or barely exserted; Filaments, 3.3-3.6 mm., tapered; Anthers versatile; Ovary inferior Pistil 1; Style exserted or barely exserted; Stigma entire; Fruit a berry, green when young, mature color and size unknown. (Described from specimen seen on Green Mountain, 2 August 2014 and Coll. No. 1252, 26-Jul-2015).
- Welch Ditch (Open Space),
4689.
4/25/2026.
4746.
4/25/2026.
.
Chenopodiaceae
Chenopodium album L. Lambsquarters. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4734.
4/25/2026.
.
 Coll. No. 1750, Chenopodium album |
 Coll. No. 3203, Chenopodium album. |
 Coll. No. 1750, Chenopodium album |
Convolvulaceae
Convolvulus arvensis L. Field Bindweed. Weed: CO DofA, List: C. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4698.
4/25/2026.
.
 Habitat of Coll. No. 1220, Convolvulus arvensis |
 Coll. No. 1220, Convolvulus arvensis |
Euphorbiaceae
Euphorbia myrsinites L. (Syn: Tithymalus myrsinites (L.) Hill ) Myrtle Spurge. Weed: CO DofA, List: A. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4713.
4/25/2026.
.
Fabaceae
Lathyrus latifolius L. Perennial Pea Vine. Weed: CO DofA, List: Watch. CalPhotos. Jepson eFlora. SEINet Taxon.
Vine, Stem winged to 3 mm., Leaves pinnate compound, main leaf axis extended as tendril, Leaflets 2, Inflorescence of 9-11 flowers, Sepals fused at base, Flower bilateral, Corolla 20 mm., wing 33 mm. wide, Stamens 10, Filaments top free, bottom 9 fused (Described from Collection No. 884, 17 August 2012).
- Welch Ditch (Open Space),
4706.
4/25/2026.
.
.
 Habitat of Coll. No. 884, Lathyrus latifolius |
 Coll. No. 884, Lathyrus latifolius |
 Coll. No. 3009, Lathyrus latifolius. |
 Coll. No. 3212, Lathyrus latifolia. |
Vicia americana Willd. American Vetch. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial herb, to 30 cm.; Stem, not winged; Leaves, stipules, 3-4 mm. × 10-15 mm. wide, reduced above, lobed, not connate, nectary 0; cauline, compound, odd-pinnate, leaflets #6-8, + simple or 2(4)-forked tendril; Inflorescence, raceme, 4-5 flowered, pedicel 17 mm.; Flowers, zygomorphic, 14-20 mm., petals, ±white to blue distally, banner sometimes pink at point of inflection; Style, round, ring of hairs below stigma; Legume, stipe 5 mm. + body 20-32 mm. × 3-4 mm. wide + persistent style 2 mm. (Described from Coll. No. 1387, 1 June 2016, and Coll. No. 1394, 1 June 2016). Specimens with fewer flowers per raceme and forked tendrils are determined variety minor.
- Welch Ditch (Open Space),
4719.
4/25/2026.
.
 Coll. No. 1394, Vicia americana |
 Coll. No. 1394, Vicia americana |
 Coll. No. 1857, Vicia americana var. minor |
Grossulariaceae
Ribes aureum Pursh. Golden Currant. CalPhotos. Jepson eFlora. SEINet Taxon.
Coll. No. 1319, 4 May 2016: Perennial shrub, to 1 m.; Stem, unarmed; Leaves, fascicled, broadly ovate, 29 mm. × 22 mm. wide, lobes 3, obtuse; Hypanthium, 9 mm., bright yellow; Sepals, petaloid, 5 mm.; Petals, 2.5 mm.; Ovary, 2 mm.
- Welch Ditch (Open Space),
4729.
4/25/2026.
.
 Habitat of Coll. No. 1834, Ribes aureum. |
 Grossulariaceae Ribes aureum |
 Grossulariaceae Ribes aureum |
 Ribes aureum in winter. |
 Twigs of Ribes aureum in winter. |
 Coll. No. 1834, Ribes aureum. |
Lamiaceae
Salvia . Horticultural Salvia. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4735. 4/25/2026. . .
Stachys byzantina K. Koch. Lamb's Ear. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4744. 4/25/2026. .
Linaceae
Linum lewisii Pursh. (Syn: Adenolinum lewisii (Pursh) A. Löve & D. Löve ) Prairie Blue Flax. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4702.
4/25/2026.
.
 Coll. No. 3119, Linum perenne. |
 Coll. No. 823, Linum lewisii |
 Coll. No. 1383, Linum perenne |
 Inflorescence of Coll. No. 1951, Linum lewisii |
Oleaceae
Fraxinus pennsylvanica Marshall. Green Ash. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4688.
4/25/2026.
.
 Coll. No. 3015, Fraxinus pennsylvanica. |
Polygonaceae
Rumex crispus L. Curley Dock. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4682.
4/25/2026.
.
 Coll. No. 2817, Rumex crispus |
 Coll. No. 818, Rumex crispus |
Rosaceae
Cotoneaster lucidus Schltdl. Hairy Stem Cotoneaster. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4683.
4/25/2026.
4693.
4/25/2026.
4711.
4/25/2026.
.
.
 Where I found Cotoneaster lucidus -- thanks to Cindy. |
 Coll. No. 2315, Cotoneaster lucidus |
Malus domestica (Suckow) Borkh. Common Apple. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4692.
4/25/2026.
.
.
 Flowers of Coll. No. 3548, Malus domestica. |
 Coll. No. 3548, Malus domestica. |
 Coll. No. 3548, Malus domestica. |
Prunus . Horticultural Prunus. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4727. 4/25/2026. . .
Prunus americana Marshall. American Plum. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial woody shrub, spreading, to 2 m., blooming before leafing out; Branches, unarmed, glabrous when young, peeling to brown; Leaves, (immature, at time of flowering), simple, 15-19 mm. × 5.5-8 mm. wide, lanceolate or elliptic-rhomboid, pinnately veined, glabrous, margin toothed, teeth eglandular, base slightly hairy, petiole 3 mm., adaxially hairy; Flowers, in small groups of 2-3; Pedicels, 9-18 mm., glabrous to sparsely hairy; Hypanthium, 2 mm.; Sepals, 2.5-2.8 mm., reflexed, few cobwebby hairs adaxially; Petals, free, white, 5-7 mm. × 2.5-4.5 mm. wide; Stamens, many (30?); Ovary superior; Styles #1, 10 mm.; Fruit unknown (Described from Coll. No. 1093, 30 Apr 2015, and Coll. No. 1819, 16 May 2018).
- Welch Ditch (Open Space),
4708.
4/25/2026.
4745.
4/25/2026.
.
.
Prunus virginiana L. Chokecherry. CalPhotos. Jepson eFlora. SEINet Taxon.
The most useful distinction is between chokecherries found east of the Rocky Mountains, var. virginiana and those found from the mountains westward, var. demissa. Plants of the High Plains show intergradation between those of the Rockies and those of the East.
- Welch Ditch (Open Space),
4680.
4/25/2026.
4690.
4/25/2026.
4724.
4/25/2026.
4743.
4/25/2026.
.
.
Rosa . Horticultural Rose. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), horticultural rose 4721. 4/25/2026. .
Rubiaceae
Galium aparine L. (Syn: Galium aparine L. var. echinospermum (Wallr.) Farw. , Galium spurium L. ) Sticky Willy, Cleavers. CalPhotos. Jepson eFlora. SEINet Taxon.
Annual/perennial unknown, weak-stemmed and scrambling through shrubs and grass; Stem, retrorsely scabrous on angles (but not densely so); Leaves, whorls of 6-8 (more leaves above, fewer below), 46 mm. × 4 mm. wide, oblanceolate, margins retrorsely scabrous, tips with a short spine; Flowers, corolla, greenish-white, lobes 1 mm.; Fruit, 1.3 mm., covered with hooked hairs (Described from Coll. No. 1395, 8 June 2016).
- Welch Ditch (Open Space),
4733.
4/25/2026.
.
 Coll. No. 1395 Galium aparine |
Salicaceae
Populus deltoides Marshall ssp. monilifera (Aiton) Eckenw. (Syn: Populus sargentii Dode ) Plains Cottonwood. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4741.
4/25/2026.
.
Santalaceae
Comandra umbellata (L.) Nutt. ssp. pallida (A. DC.) Piehl. (Syn: Comandra umbellata (L.) Nutt. var. pallida (A. DC.) M. E. Jones ) Pale Bastard Toadflax. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4703.
4/25/2026.
4707.
4/25/2026.
.
Sapindaceae
Acer negundo L. (Syn: Acer negundo L. var. interius (Britton) Sarg. , Negundo aceroides (L.) Moench ) Box Elder. CalPhotos. Jepson eFlora. SEINet Taxon.
Tree, ±5 m.; Branches, young, soft short hairy (var. interius); Leaves, opposite, ternately compound, leaflets 3; Pistil 1; Stigma, branches 2; Fruit, 2 winged 1-seeded samaras. (Described from Coll. No. 1102, 11 May 2015).
- Welch Ditch (Open Space),
4686.
4/25/2026.
4715.
4/25/2026.
4742.
4/25/2026.
.
Simaroubaceae
Ailanthus altissima (Mill.) Swingle. Tree of Heaven. Weed: CO DofA, List: C. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4730.
4/25/2026.
.
 Mature Tree of Heaven on Garden Glen Court. |
 Samara (fruit) of Ailanthus altissima “Tree of Heaven.” |
 Tree of Heaven saplings infesting a front lawn. |
 Mature Tree of Heaven on Maple Street. |
Ulmaceae
Ulmus pumila L. Siberian Elm. Weed: CO DofA, List: C. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4691.
4/25/2026.
.
 Figure 1. Composite photo of Siberian elm (Ulmus pumila L.) |
Asparagaceae
Yucca glauca Nutt. Soapweed Yucca. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space),
4710.
4/25/2026.
.
 Yucca glauca “Soapweed Yucca” on Dakota Ridge. |
Iridaceae
Iris L. Horticultural Iris. CalPhotos. Jepson eFlora. SEINet Taxon.
- Welch Ditch (Open Space), 4722. 4/25/2026. 4739. 4/25/2026. .
Poaceae
Bromus inermis Leyss. (Syn: B. inermis Leyss. ssp. inermis ) Smooth Brome. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial grass to 1 m., rhizomatous; Leaves, sheath, 8-11 cm., closed, ligule, <1 mm., membraneous, blade, 12-17 cm × 0.5 cm., flat, soft, with a distinguishing fold, usually described as an “M” or a “W” that is difficult to see when dry; Inflorescence, panicle, 15 cm. × 4 cm. wide, multiple 1° branches per node, mostly on one side of rachis; Spikelets, 1 per node on 1° and 2° panicle branches, 15-24 mm. × 5 mm. wide, laterally compressed, 2-6 florets per spikelet; Glumes, 2, keeled, glabrous, lower, 7-8 mm., veins 1 upper, 8-10 mm., <lowest floret; Rachilla, sparsely hairy on abaxial side, extended beyond uppermost floret or not; Callus, small, glabrous; Lemma, 11-12 mm., veins, 3, 5, 7, obvious, tip bifid, some awned; Awn (when present), 1.0-1.6 mm., arising near tip of lemma; Palea, 9 mm., veins ciliate. (Described from Coll. No. 1113, 26 May 2014, and Coll. No. 1219, 16 Jul 2015).
- Welch Ditch (Open Space),
4716.
4/25/2026.
.
.
Bromus tectorum L. (Syn: B. tectorum L. var. glabratus Spenn. ) Cheat Grass. Weed: CO DofA, List: C. CalPhotos. Jepson eFlora. SEINet Taxon.
Annual grass, to 30 cm.; Leaves, Sheath, 50 mm., closed proximal ⅔, open distally, Ligule, membraneous, 1 mm.; Blade, 60 mm.; Inflorescence, open panicle, rachis and pedicels short hairy, Spikelets, 1 per node, 15 mm., laterally compressed; Glumes, 2, sparsely hairy, margins scarious, lower, 2.3 mm., veins indistinct, upper, 4.5 mm. Callus, glabrous, very short, Florets, ±6, Lemma, 6.5 mm., 0.7 from mid-vein to margin, back rounded, sparsely hairy, tip, forked, teeth 1 mm., awned from near tip, awn, 5-7 mm.; Anthers, 3, 0.4 mm. Described from Coll. No. 1112, 26 May 2015. Dimensions are small for B. tectorum, perhaps because of the early date of collection.
- Welch Ditch (Open Space),
4720.
4/25/2026.
.
.
 Coll. No. 1112, Bromus tectorum |
Dactylis glomerata L. Orchard Grass. CalPhotos. Jepson eFlora. SEINet Taxon.
Perennial grass, to 1.0-1.2 m.,
not rhizomatous,
basal or subterranean internodes not swollen;
Stem herbaceous;
Leaf,
Sheath open and closed observed, published descriptions are roughly equally divided as to whether the sheath is open or closed,
Ligule membraneous, 5 mm.;
Blade, differentiated from sheath, base not constricted, soft,
25 cm. × 0.7 cm. wide, not sharp-pointed;
Auricle, rounded, <1 mm., generally described as 0;
Infloresence exceeding leaves, 13 cm., panicle, well developed, erect, 1° branches open, branching 4° or 5°;
Spikelets not enclosed in a bur-like involucre,
not subtended by bristles or long silky hairs,
similar throughout plant,
all on one side of rachis,
crowded in dense clusters,
on 2°-4° panicle branches
1 per node,
axis few hairy,
some spikelets appear to be infertile;
Glumes, 2
< lowest floret,
lower, 3.5 mm, smaller and thinner than
upper, 6 mm.,
keeled,
glabrous to ciliate on keel, else sparsely hairy;
Florets
not modified into bulblets
4+ per spikelet ,
have feathery stigma-like material but no ovary (immature?),
uppermost vestigal floret not club-shaped rudiment (as seen in Melica);
Lemma
lowest largest, 5 mm., reduced above,
keeled, line of hairs on keel,
5 veins,
tip forked,
awn 1.0-1.5 mm.;
Palea
light green
with 2 veins
forked at tip.
Described from Collection No. 815, 9 May 2012, Alameda County, CA and
Coll. No. 1111, 26 May 2015, Jefferson County, CO.
- Welch Ditch (Open Space), 4712. 4/25/2026.
| Total number of taxa: | 51 |
| Native Taxa: (serif, italic, bold) | 18 |
| Non-native Taxa: (sans-serif, italic) | 32 |
| Nativity Undetermined: (default font, italic) | 1 |
| Listed Weeds: Identified as Weed | 11 |
Notes:
† -- Data provided by the participants of the Consortium of California Herbaria (ucjeps.berkeley.edu/consortium/).
‡ -- Southwest Environmental Information Network, SEINet. 2009-2014. http//:swbiodiversity.org/seinet/index.php. Accessed from July 2009 to September 2014.
Locations Included in This Area
Bibliography
