Eastern Mojave Vegetation How did rubber rabbitbrush get that long scientific name?  

Tom Schweich  

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 Not the name “rubber rabbitbrush,” but the long scientific name Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler.

Note: The translations to English from Latin were made by me, and should be treated as suspect until proven otherwise.

  One of the more common Colorado native shrubs in Golden, and indeed along the Front Range, is commonly named “rubber rabbitbrush.” I see this growing in my neighborhood and it found its own way into my native Colorado garden. It is also found in each one of Golden's open spaces, thoughout Jefferson County, Colorado and much of the west.
  Rubber rabbitbrush has a really long scientific name: Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler. Two things piqued my interest in the names of these plants: the long list of authors attached to the names, and the history behind the names themselves. How did it get that name? And, what might it mean? And along the way can I convince you that we should call it Goldy-Locks rather than rabbitbrush?
  The story starts in Europe, long before the species was collected, when Linneus published his Species Plantarum in 1753.

Chrysocoma L.

What is the history of the genus name Chrysocoma?

The three names that remain in Chrysocoma as described by Linneaus are C. cernua, C. ciliata, and C. coma-aurea, all three of which Linneaus described as occurring in Ethiopia.

Original Text My Interpretation of the Original Text
840 SYNGENESIA: POLYGAMIA ÆQUALIS. 840 Class Syngenesia (having the stamens in each flower fused by their anthers): Order Polygamia Æqualis (The florets are all perfect or united, that is, each furnished with perfect stamens).
* Fruteſcentes.
* Shrubs.
Comå aurea. 1. CHRYSOCOMA fruticoſa, foliis linearibus dorſo decurrentibus. Hort. Cliff. 397. Hort. Upf. 252. Roy. Lugdb. 146.

Coma aurea africana fruticans, foliis linariae anguſtis, major. Com. Hort. 2. p. 89. t. 45.

Conyza æthiopica, flore bullato aureo, pinaſtri brevioribus foliis læte viridibus. Pluk. Alm. 400. t. 327.f.2.

Habitat in Æthiopia. ♄.

Chrysocoma coma-aurea 1. Yellow hair-tuft (Goldy-Locks) shrubby, linear leaves decurrent on back. Hortus Cliffortianus (Linnaeus, 1737) p. 397. Hortus Upſalienſis (Linnaeus, 1748). P. 252. Florae Leydensis (Royen, 1740) p. 146.


Shrubby African yellow tuft, narrow linear leaves, large. Com. Hort. 2. p. 89. t. 45.

Ethiopian fleabane, yellow puckered flower, lightly pine-smelling, leaves light green. Plukenet, Leonard, 1696. Almagestum botanicum … 400. t. 327.f.2.

Habitat in Ethiopia. (However, modern distribution maps suggest that this taxon is native to South Africa.)

Shrub or woody plant.

cernua. 2. CHRYSOCOMA ſubfruicoſa, foliis linearibus ſubtus piloſis, floribus ante floreſcentiam cernuis. Hort. Cliff. 397. * Roy. Lugdb. 146.

Coma aurea, foliis linariae anguſtioribus, minor. Comm. Amſt. 2. p. 89. t. 45. f. 1.

Habitat in Æthiopia. ♄.

Chrysocoma cernua 2. Yellow hair tuft (Goldy-Locks) subshrub, leaves linear underside hairy, flowers nodding before anthesis. Hortus Cliffortianus (Linnaeus, 1737) p. 397. Florae Leydensis (Royen, 1740) p. 146.


“Her hair is of gold, and the leaves of linariae more narrow, and the younger.” [Comm. Amſt. 2. p. 89. t. 45. f. 1.]

Habitat in Ethiopa. (However, modern distribution maps suggest that this taxon is native to South Africa.)

Shrub or woody plant.

Conyza [Greek, konops, flea, hence fleabane] Weber & Wittmann, 2012

(Linnaeus, 1753, p. 840 fn=Linnaeus_Chrysocoma_1.html)

3. CHRYSOCOMA ſuffruticoſa, foliis linearibus recurvis ſcabris ciliatus, floribus erectis.

Conyza africana tenuifolia ſubfruteſcens, flore aureo. Cill. Elth. 104. t. 88. f. 13.

Habitat in Æthiopia. ?.

* Herbaceae  
4. CHRYSOCOMA herbacea, foliis linearibus glabris, calycibus laxis.

Chryſocoma calycibus laxis, Hort. Cliff. 396. Roy. Lugdb. 145

Chryſocome dioſcoridis & plinii. Col. Ecphr. 1. p. 81. t. 82.

Linoſyris nuperorum. Lob. Hift. 223.

Oſyris auſtriaca. Cluf. Hift. 1. p. 325.

villoſa. 7. CHRYSOCOMA herbacea, foliis lanceolatis villoſis, calycibus arctis.

Aſter incanus, calycibus laxis oblongis, foliolis ex lineari-lanceolatis, floribus nudis umbellatis. Gmel. ſib. 2. p. 192. t. 82. f. 2.

Conyza tomentoſa & incana, floribus luteis umbellatis, echii ſcorpioidis folio. Amm. ruth. 190.

Habitat in Sibiria, Tataria.


(Linnaeus, 1753, p. 842)


Jussieu's 1774 Natural system

180  Classis X, Ordo III
Corymbiferae, Les Corymbiferes
Flores del floſculoſI omnes …
I. Receptaculum nudum. Semen pappoſum. Flores floſculoſi. (In Mutiſia, Barnadelſ, Leyſera flores radiati).
  The story in North America starts with the Lewis & Clark Corps of Discovery Expedition of 1804 to 1806. Lewis & Clark made several collections of rabbitbrush on the banks of the Missouri River. Unfortunately, the plant specimens of Lewis & Clark languished several years without description.
  It was hoped that Benjamin Smith Barton, a professor of botany and the University of Pennsylvania, and Lewis' pre-trip tutor on botany, would describe and publish the plant collections. However, Barton was too ill or uninterested to perform that task.

Frederick Pursh reviewed the collections in 1807 and prepared some drawings. However, by mid-1809 Pursh left Philadelphia for New York, then went to England in 1811 to work in the herbarium of A. B. Lambert. Pursh took with him a good deal of Lewis' herbarium, consisting of parts of specimens, thereby creating duplicates of existing specimens.

  While working for Lambert, Pursh concentrated on writing a book on American flora, his Flora Americae Septentrionalis. In it he identified 130 plants from the Lewis and Clark expedition. The collections were left in Lambert's herbarium and were auctioned after his death. One lot was purchased by Tuckerman, and eventually returned to the Academy of Natural Sciences in Philadelphia. A second lot became part of Hooker's herbarium, and upon his death, went to Kew.
  Ultimately, a total of 239 herbarium specimens have been preserved and are at three different repositories. Most, are at the Academy of Natural Sciences, with a few at Kew.
Moulton (1999) in his “The Definitive Journals of Lewis & Clark: Herbarium” assembled all the known records of likely collections of the Lewis & Clark expedition. There were three collections of what we now call Ericameria nauseosa, one of var. nauseosa, and two of var. graveolens.

The collections of today's var. graveolens were made in central South Dakota, one at the Big Bend of the Missouri, and the other at the Cheyenne River.

It is not known where or exactly when the collection of today's var. nauseosa. The date is generally agreed as October 1804, which would place the collection along the Missouri River, perhaps in central South Dakota, or a little further north along the river.

The re-assembled herbarium of Lewis & Clark contains six vouchers of Ericameria nauseosa (Moulton, 1999, pp. 20-22).

Collections of Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler

  • 39a, E. nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler, collected at the Big Bend of the Missouri River, Lyman County, South Dakota, September 21, 1804.
  • 39b, E. nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler, collected at the Big Bend of the Missouri River, Lyman County, South Dakota, September 21, 1804. Stamped: Ex Herb. A. B. Lambert.
  • 39c, E. nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler, collected above the mouth of the Cheyenne River, Dewey or Sully County, South Dakota, October 2, 1804.
  • 39d, E. nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. graveolens (Nutt.) Reveal & Schuyler, collected above the mouth of the Cheyenne River, Dewey or Sully County, South Dakota, October 2, 1804. Stamped: Ex Herb. A. B. Lambert.

Collection of Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. nauseosa

  • 40a, Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. nauseosa collected on the Missouri River, October 1804. Holotype: Chrysocoma nauseosa Pallas in Pursh, Fl. Amer, Sept. 2:517, 1814, fide L. C. Anderson, December 1985, and Velma E. Rudd, n.d. Stamped: Ex Herb. A. B. Lambert.
  • 40b, Ericameria nauseosa (Pallas ex Pursh) G. L. Nesom & G. I. Baird var. nauseosa collected at an unknown place and date but not October 15, 1805, perhaps on the Missouri River, October 1804. Isotype: Chrysocoma nauseosa Pallas in Pursh, Fl. Amer, Sept. 2:517, 1814,
  Pursh (1814, p. 517), in his Flora Americae Septentrionalis, proposed three names in Chrysocoma L. for North America taxa. The genus was used by Linneaus for some linear-leaved yellow-flowered shrubs found in Ethiopa and in Siberia. It bears the endearing common name of “Goldy-Locks.” The first name was C. nudata, which in today's form would include the authors: (Michx.) Pursh, and is today still known as Bigelowia nudata (Michx.) DC. This does not apply to a Lewis & Clark collection and does not occur in Colorado.
The second name Pursh proposed was Chrysocoma dracunculoides. This name was published by Lamarck (1786, p. 192) as Crisocome dracunculoaïde. It was applied to material Pursh saw in the Lambert herbarium (and is presumably among the Lewis & Clark specimens Pursh took to England). Collected by M. Lewis on high cliffs on the banks of the Missouri, the flower head (capitulum) was described as glabrous, which is consistent with the plant we now know as var. graveolens. The specific epithet “dracunculoides” means “dragon wort-like” referring to Artemisia dracunculus L., sometimes called dragon wort or tarragon. We now know the plant named by Lamarck in 1786 as Galatella sedifolia (L.) Greuter subsp. dracunculoides (Lam.) Greuter. Therefore, Pursh's misapplied that name to Lewis specimen. Thomas Nuttall (1818) would apply the first valid name to this plant. 2. C. glabra; foliis linearibus 3-nervibus punctato-scabris, floribus corymbosis congestis, calucibus laxis 5-floris glabris. — Lam. Encycl. 2. p. 192.

C. biflora. Sp. Pl. 1178. secundum specimen Pallasianum in Herbario Lambertiano asservatum.

On high cliffs on the banks of the Missouri. M. Lewis. ♃ Oct. v. s. in Herb. Lewis. From one to two feet high; flowers large, yellow.

2. Chrysocoma that is glabrous; leaves linear 3-nerved, punctate-scabris, flowers [in a] congested corymb, calyx loose 5-flowered glabris. — Lam. Encycl. 2. p. 192.

C. biflora. Sp. Pl. 1178. second specimen [of] Pallas preserved in Lambert Herbarium.

On high cliffs on the banks of the Missouri. M. Lewis. Perennial. Oct. seen in dried state in the Lewis Herbarium. From one to two feet high; flowers large, yellow.

The third Chrysocoma that Pursh proposed was C. nauseosa. He did this from a manuscript by Pallas that he saw in Lambert's herbarium. And while Pursh kindly tells us he saw these plants in the Lewis herbarium — “v. s. in Herb. Lewis” — he doesn't tell us that it was he who took the specimens to Europe, likely without the permission of Lewis. Regardless, since C. dracunculoides Pursh is illegitimate, then C. nauseosa is the first validly published name and will have priority over var. graveolens when we assemble them into our modern names. 3. C. calycibus pedunculis foliisque sublanato-pubescentibus; foliis angustissime linearibus, corymbo laxiusculo, calycibus laxis 5-floris: squamis interioribus divaricatis glabris. — Pallas. Mss. In Herb. Lambert.

On the banks of the Missouri. M. Lewis. ♃. Oct. v. s. in Herb Lewis. Flowers yellow, somewhat smaller than the preceding.

nauseosa 3. Chrysocoma flowerhead with calyx peduncles leafy sub-lanate to pubescent; leaves narrowly linear, corymb open, calyx open 5-flowered: interior scales diverging, glabras. — Pallas manuscript in Lambert Herbarium.

On the banks of the Missouri. M. Lewis. Perennial. Oct. seen in the dried state in the Lewis Herbarium. Flowers yellow, somewhat smaller than the preceding.

  Graustein (1967, p. 84) describes Lambert's herbarium. Of interest here is the connection to Pallas.
Original Text
Lambert, with a town house on Lower Grosvenor Street and an immense enthusiasm for botany and horticulture, was most accessible and friendly to botanical travelers, and his herbarium, one of the largest and finest in England, comprising those of Pallas (Russian plants, Asian, etc.), Ruiz and Pavon (South American), and hundreds of lesser collections, was open to scientific visitors on Saturday afternoons.
  Gray (1841, in Sprague, 1889, p. 12) writes
To the general botanist, probably the fine herbarium of Pallas, and the splendid collection of Ruiz and Pavon (both acquired by Mr. Lambert at a great expense) are of the highest interest; and they are by no means unimportant in their relations to North American botany, since the former complrises several species from the Northwest Coast and numerous allied Siberian forms, while our California plants require in some instances to be compared with the Chilian and Peruvian plants of the latter.

Nuttall's 1818 “Genera of North American Plants”

  Thomas Nuttall (5 January 1786 – 10 September 1859) was an English botanist and zoologist who lived and worked in America from 1808 until 1841. In 1811, Nuttall travelled with the Astor Expedition led by William Price Hunt on behalf of John Jacob Astor up the Missouri River. Nuttall collected something similar to the Lewis & Clark Chrysocomas, also along the banks of the Missouri. In 1815, after a few years back in England, he returned to America. After spending some more time collecting, Nuttall published The Genera of North American Plants in 1818. His first description of Chrysocoma graveolens Nutt. was included.

544. CHRYSOCOMA. L. (Goldy-locks.)
Calix imbricated, oblong or hemispherical. Style scarecely exserted. Receptacle naked. Pappus pilose, scabrous, rays crowded and unequal. Seed pubescent.
Shrubby or herbaceous; leaves alternate and entire, often narrow; flowers mostly corymbose and terminal, yellow, rarely purple; calix 3 or 4, 5, or more than 20-flowered, in C. Linosyris, &c. hemispherical, in all the North American species oblong, small, and attenuated at the base, the scales are likewise rigid and carinate. Notwithstanding this diversity of aspect, the genus appears to be perfectly natural, and presents gradations from one extreme to the other.
Species. 1. C. * graveolens. Shrubby; leaves linear, 3-nerved, smooth and impunctate; branches whitish, pulverulently tomentose; flowers corymbosely fastigiate and crowded; calix angular and smooth, 5-flowered. Hab: On the banks of the Missouri in denudated soils; common.
(Nuttall, Thomas, 1818, Vol. II, p. 136)

The holotype of Chrysocoma graveolens Nutt. Is at PH (PH00033829), collected in Montana on the banks of the Missouri River. No serial number or date is given.

Nuttall also lists C. dracunculoides of unknown distribution in a way implying (to me) that he was treating it as a synonym of C. graveolens.

Then C. nauseosa is listed as the second species.

2. nauseosa. Pallas. Herbaceous; leaves narrow, linear, as well as calix subtomentose; corymb loose; calix 5-flowered. Hab. On the banks of the Missouri; rare.
(Nuttall, Thomas, 1818, Vol. II, p. 136)

C. nudata found on the margins of swamps from Virginia to Florida, and C. virgata found on the borders of swamps in New Jersey, near the sea coast.

  While Nuttall does not mention the odor of this plant, the specific epithet “graveolens” generally means “strong-smelling,” from gravis ("heavy") + olēns ("smelling"). Nuttall placed C. dracunculoides Pursh in synonomy without noting the name was illegitimate. Nuttall also recognized the presence of C. nauseosa Pallas [ex Pursh], noting that it also is from the banks of the Missouri, and was rare.
  Then we got started with the Bigelowias and the Bigelovias.
De Candolle's 1836 “Prodromo”
  Agustin Pyramus de Candolle (1778-1841) was a Swiss botanist, working mostly in France and Switzerland, who dedicated much of his efforts trying to understand a natural system of botanical classification. In 1836, DeCandolle published Volume 5 of his “Prodromus Systematis Naturalis Regni Vegetabilis” in which published a new name called Bigelowia DC.. Apparently there were several previous uses of the name because DeCandolle stated that his was different than the Bigelowia of Spreng, Smith, or Rafinesque. The protologue of Bigelowia DC. states the receptacle has a single bristly scale between the central flowers, something Nuttall will use when he publishes his Chrysothamnus Nutt. in 1840.
  De Candolle (1836) published another name of Bigelowia and assigned the American Chrysocoma to it.

Original Text My Interpretation
CLXXXII. BIGELOWIA. DC. Non Spreng, nec Smith nec Raf. (1). -- Chrysocomae Americanae auct. CLXXXII. Bigelowia DC., not that of Spreng, nor Smith nor Raf., -- the Chrysocoma [of] America of other authors.
  De Candolle's description of his version of Bigelowia.

Original Text My Interpretation Comments
Capitulum 3-5-florum homogamum aut ligula unica foeminea heterogamum. Recept. Angustum squamam setaceam basi latisculam achaenia aequantem, inter flores centralem gerens. Invol. Oblongum, squamis paucis imbricatis erectis. Achaenia oblonga subangulosa pubescentivillosa. Pappus pilosus 1-serialis regidus scaber. -- Herbae Boreali-Americanae perennes. Folia alterna integra, caulina oblonga aut linearia. Capitula in corymbum disposita. Cor. Luteae. -- Genus differt a Linosyride pappo 1-seriali, a Chrysocoma invol. Squamis non foliaceis, ab ultraque capitulis pauci- nec multifloris, achaeniis teretiusculis nec compressis, pappo rigido, recept. Subsquamigero, etc. A Chrysocoma separatum dicavi cl. J. Bigelow qui florae Americanae auream coronam flora Bostoniensi et medica addidit. … Receptacle narrow (with a) bristly scale between the central flowers (that has a) broad base and equals (the) seeds in length, . … The reason we might care about the single bristly scale described by De Candolle (1836) in this description of Bigelowia is that Nuttall (1840) describes his Chrysothamnus as “ … Bigelowia with a naked receptacle … ”
§. 1. Genuinae. glaberrimae, capitulis 3-4-floris.
1. B. nudata, herbacea, glaberrima, foliis radicalibus spathulo-lanceolatis obtusis tenuiter 3-nerviis, caulinus distantibus linearibus, corymbo composito fastigiato, capitulis 3-4-floris. ♃ ad paludum margines a Virginia ad Floridam. Chrysocoma nudata Michx. Fl. Bor. Am. II. P. 101. Nutt. Gen. 2. p. 137. Ell.! Sketch 2. p. 309. (v.s.)
2. B. virgata, herbacea, glaberrima, foliis angustis linearibus enerviis, caule virgato ramoso, ramis corymbiferis fastigiatis, capitulis oblongis 3-4-floris, involucri squamis glutinosis adpressis. ♃ ad paludum margines in Nova-Caesarea (Nutt.) et in Florida prope Savannah (h. Dub.). Chrysocoma virgata Nutt. Gen. am. 2. p. 137. (v.s.)
§. 2. Spuriae, pubescenti-tomentose, capitulus 5-floris. -- An certe congeneres?
3. B missouriensis, herbacea tomentoso-pubescens, foliis angustis linearibus, corymbo laxiusculo, invol. 5-floris, squamis glabris, exter, patulis. ♃ ad ripas fluminis Missouri. Chrysocoma nauseosa Pursh fl. Bor. Am. 2. p. 517. Nutt. Gen. am. 2. p. 137.
4. B. dracunculoides. Suffruticosa, ramis albidis pulverulento-tomentosis, foliis linearibus 3-nerviis impunctatis, corymbo fastigiato, capitulis 5-floris, invol. Angulato laevi. ♃ in locis denudatis as ripas flum. Missouri. Chrysocoma dracunculoides Pursh fl. 2. p. 517 non Lam. Chrysocoma graveolens Nutt. Gen. am. 2. p. 136. Odor rutacens.
§. 3. Solidaginae, glabra, capitulis 5-floris, flor. 4 tubulosis, 1 ligulato. -- An Solidagini an Bigelowiae associanda?
5. B.? Uniligulata, glabra, foliis lanceolatis utrinque acuminatis serratis, panicula composita multiflora, fasciculis erectis, invol. Angusto-oblongis 5-floris, ligula unica. ♃ in Nova-Caesarea (Greene), in arenosis Virginia as Carolinam (Pursh). Solidago pauciflosculosa Michx. Fl. Bor. 2. p. 116. Pursh fl. 2. p. 537 huc pertinere videtur etiamsi nostra non habeat folia obtusa enervia nec caulem fruticosum. Vereor ne cl. Michx. Confuderit Big. Nudatam et B. pauciflosculosam. Pursh qui ex Michx. Dixit caulem frutocosum addit signum ♃, unde caract. Non videtur satis notus. (v. s. comm. A cl. Greene.)

(1) Bigelowia Smith cycl. = Borya Willd. -- Bigelowia Spr. Neu. Entd. Est ex ipso auct. Samydae spec. et Spreng. Syst. Est eadem ac Borreria. -- Bigelowia Raf. Est omnibus ignota.
  DeCandolle defined three sections of his Bigelowia DC.. His first section, Genuinae that I presume means “the genuine ones” contains B. nudata (Michx.) DC., a name still in current use. His other Genuinae, B. virgata (Nutt.) DC. is now a synonym of B. nudata (Michx.) DC.
  DeCandolle's second section of Bigelowia DC. was the Spuriae, which probably means “the spurious ones,” suggesting that DeCandolle knew these may not belong in his Bigelowia DC. Within this section, DeCandolle published a new name Bigelowia missouriensis DC., and he placed Chrysocoma nauseosa Pursh in synonomy. It is not clear why he did not simply publish nauseosa as a Bigelowia. That task was left for Marcus E. Jones (Bigelowia nauseosa M. E. Jones, Zoe 3 304 1893.)
  DeCandolle also published a second new name of Bigelowia dracunculoides DC. placing Chrysocoma dracunculoides Pursh [illeg.] and C. graveolens Nutt. in synonomy. DC noted that this plant has a rue-like odor.
Over the years many names were proposed in Bigelowia DC., and many sections were included within the Bigelowia, including the Section Chrysothamni, but ultimately only two southeastern US plants remain in the genus. Current (2016) names in Bigelowia, as accepted in FNANM, are:

  • Bigelowia nudata (Michaux) de Candolle (Syn: Chrysocoma nudata Michaux, Chondrophora nudata (Michaux) Britton)
  • Bigelowia nuttallii L. C. Anderson (1970).

The Global Composite Checklist shows three more accepted names. Though they seem somewhat dubious to me. They are:

  • Bigelowia bolanderi (A.Gray) A.Gray, basionym: Linosyris bolanderi A.Gray. This is likely a synonym of Ericameria ×bolanderi, as suggested by the Global Composite Checklist, and confirmed in Nesom & Baird (1993).
  • Bigelowia intricata A.Gray, Proc. Amer. Acad. Arts 17: 208. 1882, may be a synonym of Arida carnosa (A.Gray) D.R.Morgan & R.L.Hartm.
  • Bigelowia visciflora, accepted according to Robinson, H. 2010, Nomenclator of the Eupatorieae, unpublished, although this may also be a synonym of Brickellia linearifolia Klatt
  In Nuttall's “New Species and Genera” (1840), Nuttall published two new genera that we use today, both Ericameria Nuttall, (p. 318) and Chrysothamnus Nuttall (p. 323) His protologue for Chrysothamnus Nuttall was “Bigelowia with a naked receptacle,” i.e., that single scale on the receptacle of Bigelowia DC. is not present in Chrysothamnus Nuttall Nuttall noted that he named Chrysothamnus Nutt. from their affinity to Chrysocoma L., and brilliant golden yellow flowers; the Greek root “-thamnos” meaning bush or shrub.
  Nuttall moved DeCandolle's Bigelowia dracunculoides DC. to his Chrysothamnus dracunculoides (DC.) Nutt. rather than preserving his graveolens specific epithet with a Chrysothamnus graveolens (Nutt.) Nutt. He gave no explanation for his choice of the dracunculoides specific epithet.
  It is curious, also, that Nuttall did not place Chrysocoma nauseosa Nutt. in Chrysothamnus Nutt. That was done by Britton in 1898. Perhaps, Nuttall overlooked it, or he thought it was so rare that it might not be a viable entity.
  With this new generic name, Nuttall also gave the current Chrysothamnus viscidiflorus (Hook.) Nutt. its modern name.
In his new genus Ericameria Nuttall (1840, p. 318) placed the two sympatric plants he collected in the Blue Mountains of Oregon, and one found on the coast of Alta California. Taxa that Nuttall placed in his genus Ericameria Nuttall (1840, p. 318):

  • Ericameria microphylla Nuttall (Syn: Aplopappus ericoides DC), = Ericameria ericoides (Less.) Nutt. ex Jeps., from St. Barbara, Alta California.
  • Ericameria nana Nuttall, a currently accepted name, on rock shelves of the Blue Mountains, Oregon.
  • Ericameria resinosa Nuttall, a currently accepted name, also on rock shelves of the Blue Mountains, Oregon.

Nuttall's 1840 “New Species and Genera”

Nuttall uses an asterisk “*” to indicate new names, and a beta “β” to indicate infraspecific taxa. It's not clear whether β implies variety or subspecies.
  Nuttall (1840, p. 319) published a new name in the Compositae from plants he collected in the Blue Mountains of Oregon and Santa Barbara, California.
Capitulum few-flowered, heterogamous; rays feminine, three to six, short and oblong, three-toothed, sometimes bilabiate; discal florets about seven to nine, campanulate, five-cleft. Stigmas very long and slender, acuminate, pubescent, in the ray smooth. Receptacle naked, alveolate, dentate. Involucrum imbricate, the inner scales membranaceous on the margin, below passing into the minute leaves of the branchlet. Achenium smooth, or somewhat hirsute, linear, angular and striate. Pappus pilose, scabrous, simple, unequal. Flowers wholly yellow? -- Dwarf, often resinous shrubs, resembling heaths, exceedingly branched, branches very leafy; leaves minute and subcylindric, acerose, and semipervirent, crowded; flowers small, in a contracted, leafy corymb, or solitary and terminal. -- (So named from a resemblance to the genus Erica in the minute sempervirent leaves.)

Nuttall published three names in this new genus. Ericameria * microphylla Nutt. is considered illegitimate and the entity is now treated as E. ericoides (Less.) Nutt. Ex Jepson. E. ericoides is a California endemic found in sand dunes or sand hills along and near coast from Los Angeles to Sonoma counties.

Ericameria * nana Nutt. and E. * resinosa Nutt. are both accepted names for plants that Nuttall collected in the Blue Mountains of Oregon. Today, E. nana Nutt. is known from arid rocky plains, desert mountain cliffs, and crevices; 1300–2900 m; in California, Idaho, Montana, Nevada, Oregon, and Utah. E. resinosa Nutt. is known from rocky plains, steep hillsides, and cliff faces, often on basalt; 100–1000 m; in Idaho, Oregon, and Washington.

  Nuttall (1840, p. 323) published Chrysothamnus but he did not move Chrysocoma graveolens.
BIGELOWIA, but with the receptaculum naked. Capitulum five to eight-flowered; branches of the stigma filiform, cylindric, exserted, acute, pubescent nearly their whole length. —Very branching shrubs of the western interior and Rocky Mountain plains, with entire, equal, linear leaves, and fastigiately clustered flowers. Most of the species more or less resinous, and with a heavy aromatic odour. —(Named from their affinity to Chrysocoma, and brilliant golden yellow flowers.)
Chrysothamnus * pumilus; shrubby, dwarf, smooth or pulverulently pubescent; leaves narrow linear, acute, partly three-nerved; involucrum about five-flowered.

HAB. On the borders of Lewis' River and the Rocky Mountain plains. A low shrub, much branched from below, about six inches high; flowers in terminal, fastigiate clusters. Involucrum smooth or glutinous. β. * Euthamioides; involucrum ovate, the scales ovate and short. Perhaps a distinct species.

C. pumilis Nutt. is now treated as a synonym of Chrysothamnus viscidiflorus (Hooker) Nuttall subsp. viscidiflorus (Syn: C. viscidiflorus subsp. pumilus (Nuttall) H. M. Hall & Clements). Widespread throughout the western slope and north central counties, apparently absent from San Luis Valley.

C. pumilis (var.) euthanmoides Nutt. was placed in Bigelowia douglasii A. Gray var. pumila by Gray (1884). However, now it appears more likely to be subsumed into Chrysothamnus viscidiflorus (Hooker) Nuttall ssp. puberulus (D. C. Eat.) Hall & Clem. (Munz, 1965). Not known from Colorado.

Chrysothamnus * speciosus; shrubby and virgately branched; leaves narrow, linear, acute, more or less tomentose; capituli in dense, conglomerate, terminal clusters, five-flowered; style hirsute, elongated; pappus copious, scarcely scabrous.

HAB. In the Rocky Mountain plains, near Lewis' River, common. Flowering in August.

C. speciosus Nutt. is now treated as a synonym of Ericameria nauseosa var. speciosa (Nutt.) G.L.Nesom & G.I.Baird
β * albicaulis; stem densely and whitely tomentose; perhaps a distinct species. Showy shrubs, three or four feet high, with numerous virgate branches, like the common Broom. Leaves one-nerved, scarcely half a line wide, one and a half to two inches long. Flowers abundant, brilliant yellow.

I assume the “β” signifies that Nuttall is naming a variety; therefore the taxon name is Chrysothamnus speciosus Nutt. Var. albicaulis Nutt., which now seems to be a synonym of Ericameria nauseosa var. speciosa (Nutt.) G.L.Nesom & G.I.Baird. It is found in northwestern Colorado, with one collection in Mesa County.

Chrysothamnus dracunculoides. Bigelowia dracunculoides, Decand., Vol. V. p. 329.

HAB. Rocky Mountain plains, near the banks of the Platte and Missouri. A shrub three to five feet high, with a heavy, unpleasant, though somewhat aromatic odour.

Chrysothamnus dracunculoides (DC.) Nutt. is a synonym of Ericameria nauseosa var. graveolens (Nutt.) Reveal & Schuyler, which is common and widespread throughout the state of Colorado.
Chrysothamnus viscidiflorus. Crinitaria viscidiflora, Hook. Flor. Bor. Am., Vol. II, p. 24. With this plant I am unacquainted, but it agrees well with the present genus.

Capitulum six to eight-flowered; stigma ligulate.

Chrysothamnus lanceolatus; shrubby, nearly smooth; leaves linear-lanceolate, acute, three-nerved, somewhat glutinous; capituli corymbosely clustered, six to eight-flowered; stigma ligulate, pubescent at the apex.

HAB. In the Rocky Mountains, toward the sources of the Platte, and on the banks of Lewis' River of the Oregon. A moderate-sized shrub, with broader leaves than usual, one to one and a half inches long, by three to four lines wide, slightly puberulous. Involucrum of about four series of ovate, concave, acute scales. Stigma exserted, flat, with an ovate puberulous apex, something like that of the true Bigelowias. Pappus white, not abundant, scabrous. Florets pale yellow.

C. lanceolatus Nutt. is a synonym of C. viscidiflorus subsp. lanceolatus (Nutt.) H.M.Hall & Clem. This taxon is widespread throughout the central and western counties of Colorado, including the San Luis Valley, 5500-10,500 ft.

  Torrey & Gray (1841, p. 232) proposed that the North American Chrysothamnus be included in the European and Asian genus Linosyris. While the flora was published by John Torrey and Asa Gray, later publications will focus on Gray's contribution to this decision, and tend to leave Torrey out of it. See, for example, Greene (1895).
  Gray proposed Linosyris graveolens retaining Nuttall's specific epithet, so today we might list the authorship as “(Nutt.) Torr. & A. Gray.” Curiously, the Plant List identifies L. graveolens as an unresolved name, which may be a synonym of Ericameria nauseosa var. graveolens (Nutt.) Reveal & Schuyler. And, similarly, the Global Composite Checklist, has L. graveolens (Nutt.) Torrey & Gray as an unknown name, though it does show C. graveolens Nutt. as the basionym.

Regardless, Torrey & Gray were clear about what entity they wanted to give this name, in that they placed the following names in synonomy with their proposed Linosyris graveolens:

  • Chrysocoma graveolens Nuttall
  • Chrysocoma dracunculoides Pursh, which today we would designate illegitimate.
  • Bigelowia dracunculoides DC
  • Chrysothamnus dracunculoides Nuttall (in trans. Amer. phil soc. l. c. p. 324) -- not sure what this is!
  Gray was not so sure about Chrysocoma nauseosa Pursh. He thought it could be a subspecies of Linosyris graveolens, along with Bigelowia missouriensis DC. and Chrysothamnus speciosus Nuttall.

Alternatively, it could also be a synonym of Linosyris albicaulis, with Chrysothamnus speciosus ß albicaulis Nuttall.

Today, we would look askance at this reduction of C. nauseosa Pursh to a synonym, because it was clearly published before any of the alternatives. But, at that time, there was no code of botanical nomenclature, and the principle of priority of names was not well established.

Gray in Torrey & Gray (1841, p. 236) left Ericameria of Nuttall (1840) mostly untouched with the exception of adding a few synonyms. One of those synonyms, Diplopappus ericoides Less., is important because it is the basionym for the currently accepted name of Ericameria ericoides (Less.) Nutt. ex Jeps. This plant is currently found in coastal California, from Los Angeles county north to Sonoma County. Taxa that Torrey & Gray (1841, p. 236) left in Ericameria:

  • Ericameria microphylla Nuttall (Syn: Diplopappus ericoides Less., Aplopappus ericoides DC, Aplopappus ericoides Hook. & Arn.), from St. Barbara, Alta California.
  • Ericameria nana Nuttall, on rock shelves of the Blue Mountains, Oregon.
  • Ericameria resinosa Nuttall, also on rock shelves of the Blue Mountains, Oregon.
Did George Engelmann publish Linosyris graveolens var. glabrata Engelm. and, if so, when and where?

There is no record of this name in Global Composite Checklist, the Plant List, or Tropicos.

Why do we care? Because Gray (1873) cited this name as a synonym of Bigelowia graveolens var. glabrata A.Gray, which Neson & Baird (1993) then cited as the basionym of their Ericameria nauseosa var. glabrata (A.Gray) G.L.Nesom & G.I.Baird

Publications in which Engelmann might have published the name:

Catalogue of a collection of Plants made in Illinois and Missouri. by Charles A. Geyer; with critical remarks, &c. In: American Journal of Science and Arts. Vol 46, 1844, P. 94–104, (online).

Plantae Lindheimerianae: An Enumeration of the Plants collected in Texas, and distributed to Subscribers, by F. Lindheimer, with Remarks, and Descriptions of new Species, &c. In: Boston Journal of Natural History. Vol 5, 1845, P. 210–264, (online). - with Asa Gray

Botanical Appendix. In: Friedrich Adolph Wislizenus: Memoir of a Tour to Northern Mexico: Connected with Col. Doniphan's Expedition, in 1846 and 1847. Tippin & Streeper, Washington 1848, S. 87–115, (online).

In: Asa Gray: Plantae Fendlerianae Novi-Mexicanae: An Account of a Collection of Plants made chiefly in the Vicinity of Santa Fé, New Mexico, by Augustus Fendler; with Descriptions of the New Species, Critical Remarks, and Characters of other undescribed or little known Plants from surrounding Regions. Boston 1848.

In: Asa Gray: Plantae Lindheimerianae, Part II. An Account of a Collection of Plants made by F. Lindheimer in the Western part of Texas, in the Years 1845-6, and 1847-8, with Critical remarks, Descriptions of new Species, &c.. In: Boston Journal of Natural History. Vol 6, 1850, S. 141–240, (online).

On the Character of the Vegetation of South Western Texas. In: Proceedings of the American Association for the Advancement of Science. Vol 5, 1851, S. 223–229, (online).

In: Asa Gray: Plantae Wrightianae texano-neo-mexicanae: An account of a collection of plants made by Charles Wright. Smithsonian Institution, Washington 1852–1853.

In: Asa Gray: A Manual of the Botany of the Northern United States. 2. Auflage, George P. Putnam & Co., New York 1856.

Botany. In: Ferdinand Vandeveer Hayden: On the Geology and Natural History of the Upper Missouri. In: Transactions of the American Philosophical Society. Neue Folge, Vol 12, 1861, S. 182–212, (online).

  Nuttall (1848) argued against Torrey & Gray's reduction of Chrysothamnus to a synonym of Linosyris.
Original Text
Chrysothamnus, by Torrey and Gray, had been referred to the genus Linosyris, of the old world, with which, as I conceive, they have little if any affinity, as must appear on comparing the characters of the two genera. Taking L. vulgaris for the type of the genus, we observe that the hemispherical involucrum is scarcely imbricated, leafy externally, with about one row, or scarcely two of scales, which are learly flat ; the florest very numerous, are very deeply divided ; the stigmas are elongated ; the summit or appendage short and ovate, much shorter than the lower or stigmatic portion. Pappus very copious, and scabrous, in several series, scarcely longer than the achenium. Achenium oblanceolate, and compressed, sericeous villous, with only two marginal lines. Receptacle conspicuous, with alveolar margins.
In the present genus the involucrum is imbricated distinctly, in three to five series of subcarinated scales, the lowest very small. The florets few in number, have a short, five-cleft border. The processes of the style are long and subulate, much exceeding the lower, naked portion. Pappus slender, much less copious, and not so scabrous as in the preceding; more than double the length of the achenium. Achenium somewhat cylindric, smooth, about five lined. Receptacle very small and smooth.
  Gray, Engelmann, and others, patronized a collecting trip Augustus Fendler to Santa Fe, New Mexico in 1846-1847. Gray published the list of species in Plantae Fendlerianae Novi-Mexicanae (1849)

Gray was still using Linosyris for the Chrysothamni, although Fendler apparently only collected one plant (Gray, 1849, p. 75).

352. Linosyris graveolens, β. Torr. & Gray, Fl. 2. p. 234. Dry, gravelly hills, Bent's Fort, on the Arkansas; Sept. (341.) — “Shrub 2 to 4 feet high.” — The Linosyris Texana, Torr & Gray, l. c., was founded on specimens which prove to be masculine individuals of a nearly herbaceous species of Baccharis.*
  By 1873, Gray, in his “Notes on Compositae and Characters of certain Genera and Species” stopped using Linosyris and proposed, instead, Bigelovia with a “v” rather than a “w.” This is the same as Bigelowia DC. that de Candolle proposed in 1836.

However, most current (2016) data bases use the Bigelowia with a “w,” while the Bigelovia with a “v” is relegated to synonomy with plants in various families, including Rubiaceae and Salicaceae.

Gray demoted Chrysothamnus to the rank of Section, adding many other taxa within the five sections in Bigelovia. Gray's (1873) sections of Bigelovia Gray.
  1. Diplostephioides
  2. Aplodiscus
  3. Chrysothamnopsis
  4. Chrysothamnus
  5. Eubigelovia
Comments Original Text My Interpretation
Gray lumped all the western Sect. Nauseosi into a single name of Bigelovia graveolens Gray, and then proceeded to enumerate four varieties that he said were the most “… marked deviations …” from “… numerous inseparable forms.” This is something that Marcus Jones would object to in 1893.

For his var. glabrata, Gray cited Linosyris graveolens var. glabrata Engelm. as a synonym. To date (October, 2018), I have been unable to confirm that Engelmann actually published, proposed, or otherwise wrote about that name.

Maybe some words are needed here about the eastern establishment botanists, such as Asa Gray, who tended to be more herbarium-bound (“closet-botany”). In the west, botanists, such as Edward Greene, Aven Nelson, and Marcus E. Jones, tended to be more field-oriented. and therefore more familiar with the plants when they were fresh. Greene used plant odor, such as terpenes derived from plant chemistry, as a distinguishing character, perhaps because he had smelled a field rabbitbrush. On the other hand, Gray never used odor as a character, perhaps because because most of the specimens he worked with were dry and the odoriferous compounds had evaporated. Perhaps this is what led Gray to lump the Nauseosi together in his B. graveolens with the thought that they were generally inseparable. For more on this issue see: Williams (2003, pp. 50, 123).

22. B. GRAVEOLENS. Fruticosa, 1-4-pedalis, primum pl. m. lanata, tomento nunc copioso implexo derasibili nunc tenui evanescente ; ramis virgatis; foliis aut angustissime linearibus mox involutis aut latioribus planis; capitulis semipollicaribus; involucri squamis oblongis vel lanceolatis obtusiusculis vel obtusis; corollae limbo breviter 5-lobo; appendicibus styli subulato-filiformibus parte stigmatica longioribus; pappo satis molli. — B. dracunculoides & B. Missouriensis DC. Prodr. 5, p. 329. Chrysocoma dracunculoides (non Lam.) & nauseosa Pursh. C. graveolens & nauseosa Nutt. Gen. Chrysothamnus dracunculoides & speciosus Nutt. Trans. Amer. Phil. Soc. Linosyris graveolens & albicaulis Torr. & Gray, Fl. 2, p. 234. — Plains, etc., Western Arkansas to Dakota, and west to California and Washington Territory. — Exhibits numerous inseparable forms, of which the most marked deviations from the general type are: —

Var. glabrata.(Linosyris graveolens var. glabrata Engelm.) Primum tomento tenui cinerea, mox glabrata viridis; involucri squamis saepius angustioribus subacutis; corollae lobis paullo longioribus.

Var. latisquamea …

Var. hololeuca …

Var. albicaulis … — Chrysothamnus speciosus var. albicaulis Nutt., Linosyris albicaulis Torr. & Gray.

22. B. GRAVEOLENS. Bushy, 1-4 feet, most plants wooly, hairs fully entangled to appear vanishing ; branches [like] twigs; leaves narrowly linear becoming curled or wide planes; heads “semipollicaribus;” involucre scales (phyllaries) lanceolate to oblong, [tips] obtuse to “obtusiusculis;” corolla limb short, 5-lobes; style appendages subulate-filiform, stigmatic part long; pappus quite soft. — B. dracunculoides & B. Missouriensis DC. Prodr. 5, p. 329. Chrysocoma dracunculoides (non Lam.) & nauseosa Pursh. C. graveolens & nauseosa Nutt. Gen. Chrysothamnus dracunculoides & speciosus Nutt. Trans. Amer. Phil. Soc. Linosyris graveolens & albicaulis Torr. & Gray, Fl. 2, p. 234. — Plains, etc., Western Arkansas to Dakota, and west to California and Washington Territory. — Exhibits numerous inseparable forms, of which the most marked deviations from the general type are: —

Var. glabrata.(Linosyris graveolens var. glabrata Engelm.) Most common thin gray hairy gray, less common glabrous green; cover scales often narrower subacute; corolla lobes slightly longer.

Var. latisquamea …

Var. hololeuca …

Var. albicaulis … — Chrysothamnus speciosus var. albicaulis Nutt., Linosyris albicaulis Torr. & Gray.

  Gray's (1884) Syntopical Flora of North America …
  Gray proposed Chrysothamnus as Section 2 of Bigelovia
  1. Chrysothamnopsis
  2. Chrysothamnus
  3. Eubigelovia
  4. Euthamiopsis
  5. Aplodiscus
  Bigelovia graveolens var. glabrata (Syn: Linosyris graveolens var. glabrata Engelm.) … but not Chrysocoma graveolens or C. dracunculoides Pursh [illeg.]
  Gray proposed Chrysocoma nauseosa to be a synonym of Bigelovia graveolens var. albicaulis
Gray (1884, p. 125) also placed Ericameria Nuttall as a section of Aplopappus Cassini, which we have now come to know as Haplopappus Cassini. The roots of the name are Greek, and mean “simple pappus.” Gray's (1884) sections of Aplopappus Cassini were:

  1. Prionopsis
  2. Aplopappus proper.
  3. Isopappus
  4. Stenotus
  5. Ericameria, including:
    • A. cuneatus Gray (Syn: Bigelovia spathulata Gray, B. rupestris Greene) = Ericameria cuneata (A.Gray) McClatchie
    • A. laricifolius Gray = Ericameria laricifolia (A.Gray) Shinners
    • A. monactis Gray = Ericameria cooperi (A.Gray) H.M.Hall
    • A. ericoides Hook. & Arn. (Syn: Ericameria microphylla Nuttall = Ericameria ericoides (Less.) Nutt. ex Jeps.
    • A. Palmeri Gray = Ericameria palmeri (A.Gray) H.M.Hall
  6. Macronema Nuttall
I think that Gray has confounded two well-marked species of Bigelovia in his cosmopolitan B. graveolens. One has a thyrsiform inflorescence, cylindric campanulate corolla with reflexed or widely spreading lobes a line long, and usually glabrous stems and leaves; it grows 1 to 3 feet high. This is the B. graveolens Gray, really (Nutt). The other species is what should be called B. nauseosa (Pursh) and is the Linosyris albicaulis T. & G. This is also B. graveolens var. albicaulis Gray, and will include as varieties of it var. latisquama (Gray) and var. hololeuca (Gray). The type has a fusi-form corolla, lobes almost never spreading and never reflexed, usually closed, often short; corymbiform inflorescence, usually flat topped with many heads, occasionally corymbs with few heads and somewhat thyrsiform in outline; stems white tomentose. The corolla is generally with closed lobes and then the fusiform character is very evident; it is always a little contracted at throat. The " cobwebby hairs" are found on all forms of the B. graveolens of Gray and are of no value.
  ... Chrysocoma graveolens was placed in Chrysothamnus by Greene in 1895

Greene's 1895 “Notes on the Compositae -- IX.”

I have long thought that the establishment of the genus Chrysothamnus was one of Nuttall's happiest propositions. He saw that these tufted shrubs of western alkaline plains were generically distinct from DeCandolle's Bigelovia.
And Gray, his young colleague in the study of these plants, was of the same opinion. It was unfortunate that Gray, instead of following Nuttall as to the new genus, should have chosen to follow one far less deserving to be taken as an authority.
Schelchtendal had, in 1839 or 1840, referred a Mexican species of what was of Nuttall's genus Isocoma to that Old World subgenus of Aster called Linosyris; and Gray, in the Torrey & Gray Flora proceeded, in the face of Nuttall's greatly superior knowledge of botany in general, and of these plants in particular, to dispose all the Chrysothamni under the Old World herbaceous genus Linosyris.
This course, entered upon in much ignorance as to the real characteristics both of the foreign Linosyris, and of the to him almost equally foreign shrubs of western plains and mountains, he held to for more than thirty years.
But in 1873, Bentham, when he came to take up the final examination of all known Asteroideae, soon demonstrated the absence of near affinity between Linosyris proper and these shrubs of the Far West, and perceived the necessity of reinstating Nuttall's Chrysothamnus. This was done in the Genera Plantarum; and I think we should have had little further trouble with the nomenclature of these plants had not Bentham merged in his Chrysothamnus the herbaceous genus Bigelovia, i. e., Chondrophora.
At this juncture Gray asserted the priority of Bigelovia over Chrysothamnus, and so all the species became renamed under Bigelovia; Bentham himself accepting, in the Addenda et Corrigenda of his volume, the name Bigelovia instead of Chrysothamnus.
I have already expressed the opinion that Chondrophora and Chrysothamnus are not properly congeneric; that the plant which comes nearest to forming a connecting link between these two is Petradoria, a species which no one has yet referred to either genus. As compared with Chondrophora the typical Chrysothamni have corollas less deeply cleft and segments less recurved; style-tips more slender and exserted; achenes larger, narrower and more pubescent, with few angles, and a much less firm as well as often more copious and elongated pappus. They are all shrubs with a very hard wood; and their branches are leafy throughout, the leaves being all alike, i. e., the lower not differing from the upper.

Greene's 1895 “Notes on the Compositae -- X.”

In 1895, Greene expressed some doubt that the Sect. nauseosi belonged in Chrysothamnus
All the shrubs that follow are still more notably, are more concordantly, diverse from the typical Chrysothamnus. They are of coarser and more broom-like growth, with softer more pithy wood, and the stems are usually clothed at least when young, with a dense white tomentum. The twigs and foliage, when bruised, exhale a disagreeable odor of which there is no trace in the typical group. The corollas are usually if not always nearly destitute of a proper limb, the throat being elongated and almost or quite claviform, with only short suberect teeth in place of the usual larger and more or less spreading segments, and the style-tips are as commonly, perhaps quite invariably, elongated and filiform like those of the genus Macronema, the one discoid species of which is often mistaken by the inexperienced for “Bigelovia Bolanderi” which differs from this group of Chrysothamnus by its involucre only.
I have long been in a state of hesitancy as to whether this group should not be received as generically distinct from true Chrysothamnus. And again, if these shrubs do not belong to this genus, there is room for dispute as to whether they should form a genus by themselves, or be referred to Macronema, or to the South American Dolichogyne, to which last they bear a striking general resemblance. But the types of Dolichogyne have peculiar style-tips, rather too unlike those of any of our plants; and the bristles of the pappus are perceptibly flattened. But for these two peculiarities of Dolichogyne I should relegate to it all the following:
Original Text Comments and Interpretation
12. C. graveolens. Chrysocoma graveolens, Nutt. Gen. ii. 136 (1818). Linosyris graveolens, T. & G. Fl. Ii. 234 (1842). Bigelovia graveolens, var. glabrata, A. Gray, Proc. Am. Acad. Viii. 645 (1873). Chondrophora nauseosa glabrata, Rydb. Mem. Torr. Club, v. 317 (1894). Bigelovia dracunculoides, DC. Prodr. V. 329 (1836). Chrysothamnus dracunculoides, Nutt. Trans. Am. Phil. Soc. 325 (1840). Stout, very leafy almost glabrous shrub usually 3 or 4 feet high, the numerous long branches ending in an ample rounded cymose corymb, the branches of which are more or less tomentulose; leaves ascending, narrowly linear, very acute, 2 or 3 inches long, obscurely 3-nerved, glabrous: involucral bracts about 4 in each vertical rank, acute, glabrous even to the margin: corolla with slender tube glabrous or with a few short hairs; the nearly cylindric throat cleft a fourth to a third the way down; pubescence of the achenes abundant, long, appressed, not very fine: style-appendages at least twice the length of the stigmatic portion.  
Abundant on alkaline plains east of the Rocky Mountains, from the upper Arkansas and Platte, ranging northeastward to Dakota, then westward along the line of the British boundary possibly as far as British Columbia. Apparently not in the Great Basin unless eastwardly about Salt Lake.  
It was doubtless this species which Pursh mistook for the Asiatic Chrysocoma dracunculoides (now Aster dracunculoides) and which in consequence of this error became Bigelovia dracunculoides, DC., and Chrysothamnus dracunculoides, Nutt. Greene is suggesting here that Pursh mistook Lewis & Clark's collection as the Siberian Crisocome dracunculoides Lamarck. I think this is correct. We now know the plant named by Lamarck in 1786 as Galatella sedifolia (L.) Greuter subsp. dracunculoides (Lam.) Greuter.
13. C. speciosus, Nutt. Trans. Am. Phil. Soc, vii. 323 (1840). Chrysocoma nauseosa, Pall. In Pursh Fl. Ii. 517 (1814)?? Size of the preceding, but stems more slender, inflorescence more open: leaves very narrowly linear, and with the branchlets of the inflorescence minutely white-tomentose: involucral bracts firm, acutish, not ciliate, tomentose on the back, or the inner ones glabrous except near the tip, all in vertical ranks of 3 or 4: corolla with slender almost glabrous tube rather longer than the subcylindric throat, this cleft a third of the way down: pappus copious, fine, only delicately scabrous, fuscous at least in age.

A far-western species, the type being of the upper Missouri, but common in Idaho, eastern Oregon, northwestern California and adjacent Nevada. Easily distinguished from C. graveolens by its slender habit, and almost filiform white leaves.

Chrysothamnus speciosus Nutt. And var. plattensis Greene, below, are both synonyms of Ericameria nauseosa var. speciosa (Nutt.) G.L.Nesom & G.I.Baird (Syn: Chrysothamnus nauseosus (Pall. Ex Pursh) Britton subsp. albicaulis (Nutt.) H. M. Hall & Clem.)

? Var. (?) Plattensis. Low and merely suffrutescent; seldom a foot high, very leafy, the long narrowly linear white-tomentose leaves spreading or recurved: involucral bracts about 3 in each vertical rank, acute, glabrous except that the margins are rather densely woolly-ciliate: tube of corolla somewhat pubescent; throat elongated, rather deeply cleft. Plentiful on alkaline plains of the Platte and elsewhere along the eastern base of the Rocky Mountains; associated with C. graveolens, but very distinct from that, flowering earlier; referable to C. speciosus unless a distinct species. This will probably be the Chondrophora nauseosa of Britton Mem. Torr. Club. V. 317.
Chrysothamnus speciosus var. plattensis Greene is a synonym of Ericameria nauseosa var. speciosa (Nutt.) G.L.Nesom & G.I.Baird
15. C. frigidus. Chrysocoma nauseosa, Pall. In Pursh?? Stoutish, seldom 2 feet, often less than one foot high, the branches of the season erect, numerous, whitish-tomentose : leaves narrowly linear, seldom 2 inches long, acute, erect or ascending, distinctly white-tomentose, seldom glabrate : heads mostly thyrsoid-panicled, 4 or 5 lines high, bracts in not very distinct vertical ranks, the outer acute, the inner obtusish, all more or less tomentulose and glandular, the margins delicately ciliate at least near the summit : corolla-tube sparingly short-hairy, not at all elongated, widening gradually to the abruptly subclaviform rather deeply cleft throat: style-appendages much longer than the wholly included stigmatic part.

Plentiful on the elevated bleak plains about Laramie, Wyoming, and eastward to the borders of Utah. Without knowledge of the type specimens it is impossible to say whether this plant or our number 13 is the basis of the scarcely published Chrysocoma nauseosa of Pursh's Flora.

Chrysothamnus frigidus Greene is now a synonym of Ericameria nauseosa var. nauseosa.

Britton and Brown's 1898 “Illustrated Flora of the Northern United States”


Britton & Brown's (1898) first edition of An Illustrated Flora of the Northern United States, Canada, and the British Possessions incorrectly equated Chrysocoma nauseosa Pursh and C. graveolens Nuttall. This was corrected in their second edition (1913).

I. Chrysothamnus nauseosus (Pursh) Britton. Fetid Rayless Golden-rod. (Fig. 3662.)
C. nauseosa Pursh, Fl. Am. Sept. 517. 1814.
C. graveolens Nutt. Gen. 2: 136. 1818.
Bigelovia graveolens A. Gray, Proc. Am. Acad. 8: 644. 1873.
Chondrophora nauseosa Britton, Mem. Torr. Club, 5: 317. 1894.

Densely white-tomentose, at least when young, much branched, very leafy, 1°–6° high, odorous. Leaves linear, or slightly spatulate, 1'-2' long, 1"-2" wide; heads 5"-8" high, very numerous and crowded in terminal compound corymbose cymes, rays none; involucre narrowly campanulate, acute at the base, its bracts oblong or linear-oblong, acutish, puberulent, imbricated in about 4 series; achenes linear; pappus-bristles soft, copious.

In sterile, especially alkaline soil, Northwest Territory to western Nebraska (?) and New Mexico, west to British Columbia and southern California. Aug.-Oct.


Britton and Brown's (1913) Illustrated Flora …

16. CHRYSOTHAMNUS Nutt. Trans. Am. Phil. Soc. (II) 7: 323. 1840.

Low shrubs, with equably leafy branches, hard wood, linear leaves, and discoid heads of yellow perfect flowers. Heads narrow, 5-7-flowered. Involucre oblong to narrowly campanulate, its bracts more or less keeled, thin, or papery, impricated in several series, often so as to form 5 vertical rows. Corolla 5-toothed. Anthers obtuse at the base. Style-branches exserted, their appendages subulate to filiform. Achenes narrow, mostly pubescent. Pappus of copious capillary roughened bristles. [Greek, golden-bush.]

About 30 species, natives of western North America. Type species: Chrysothamnus pumilus Nutt.

  Britton and Brown (1913) accept Greene's placement in Chrysothamnus.

I. Chrysothamnus gravèolens ( Nutt.) Greene. Fetid Rayless Goldenrod. Fig. 4204.

Chrysocoma graveolens Nutt. Gen. 2: 136. 1818.
Bigelovia graveolens A. Gray, Proc. Am. Acad. 8: 644. 1873.
Chrysothamnus graveolens Greene, Erythea 3: 108. 1895.

Sparingly tomentose above, or glabrate, much branched, very leafy, 1°-4½° high, odorous. Leaves linear, 1'-3' long, 1"-2" wide ; heads 5"-6" high, very numerous and crowded in terminal compound corymbose cymes; rays none; involucre narrowly campanulate, acute at the base, its bracts oblong or linear-oblong, acute or acutish, imbricated in about 4 series; achenes linear; pappus-bristles soft, copious.

In sterile, especially alkaline soil, Montana to western Nebraska, Utah and New Mexico. Included in our first edition in the C. nauseosa (Pursh) Britton, a densely tomentose far western species. Rabbit-brush. Aug.—Oct.
Piper (1906) Flora of the State of Washington
Piper (1906) seems to be the first guy to place graveolens as a subspecies of nauseosa, whereas H. M. Hall published graveolens as a variety of nauseosa in 1919. (University of California Publications in Botany 7(6-8): 174 1919.
  Some of the folklore to which I was subjected early in my meager education about desert shrubs was that “rubber rabbitbrush,” which I now know as Chrysothamnus, could be a viable source of rubber. This was also about the time of the 1970's Arab Oil Crisis and there was a collective hysteria about finding all kinds of alternatives to traditional sources of raw materials. For example, Jojoba (Simmondsia chinensis (Link) C. K. Schneid.) was thought to be an economically-viable source of oil, and whole plantations of jojoba were being planted. Anyway, I suspect that the facts of obtaining rubber from rabbitbrush probably originated from this series of papers by Hall and Goodspeed (1919). Generally, it is true that a good rubber can be obtained from rabbitbrush, but time has shown that it is not really economically viable.

Chrysil is the name adopted for the particular kind of rubber found in Chrysothamnus nauseosus. The rubber occurs in the individual cells, and is not a latex-rubber. It is a rubber of high grade and vulcanizes without difficulty. Chrysil occurs in the plant in the greatest amount at about the soil line. The richest tissues are found in the cortex and the medullary rays, the former carrying much more than the latter.

The most important species of Chrysothamnus is C. nauseosus. Rubber was found in all varieties, although individual plants may be devoid of rubber. The best varieties were those which inhabit alkaline soils.

Variety Average
pinifolius2.69% now = E. nauseosa var. oreophila
viridulus2.52% now = E. nauseosa var. unnamed.
consimilis1.97% now = E. nauseosa var. oreophila

Other varieties had lower percentages of rubber. Variety graveolens was much lower in the list with an average of 0.83% rubber (min: 0.07%, max: 3.19%), and variety nauseosus contained only trace amounts.

The highest absolute percentage was found in a plant of consimilis collected near Gerlach, Nevada, which analyzed 6.57% of pure rubber. The second-highest was a plant of viridulus from Benton California, which yielded 5.56%.

The largest stands of Chrysil-bearing shrub are in Colorado, Nevada, and Utah. The plants with the highest rubber content are from Nevada and California. The total amount of rubber present in wild shrub was estimated at over 300 million pounds.

  Hall & Goodspeed's (1919, p. 186) paper … “Professor Marcus E. Jones informs us that steps were taken about 1908 to erect a rubber-extraction plant at Salida, Colorado, the intention being to use Rabbit-brush but the plan fell through. ” Searches for information about "Salida" and "rubber" show that the plant in use was Hymenoxis richardsonii rather than Ericameria nauseosa. See my page on Hymenoxis richardsonii, which is linked at left.

Footnote 3 on the same page, refers to …

… a factory [that] was in operation at Durango, Colorado, as early as 1905 and that the company in charge of it actually placed upon the market rubber made from “Rabbit-weed.” However, the results of further inquiry indicate that almost with certainty that the plant used was not Chrysothamnus, but the “Colorado Rubber Plant” (Hymenoxys floribunda utilis).
Hall (1919) is the earliest reference I have seen to the gray and green forms of Chrysothamnus nauseosus. They describe the appearance:

… The felt-like covering to the twigs is more or less infiltrated with a resinous substance. In some forms the surface us usually light gray or dull white or even almost pure white, and the loose tomentum extends even to the involucres. The original C. nauseosus is one of these forms. In other varieties the surface of the tomentum is firm and smooth, thus revealing the striae. In these forms the twigs are dull to bright yellowish green in color or rarely somethat whitish and the involucres are mostly glabrous (Hall, 1919, p. 161) …

The criteria for designating a variety of C. nauseosus as a gray form or a green form suggest that the tomentum is loose and extends to (includes) the involucre. For variety nauseosus this is true. However, it is only half-true for var. graveolens, because the involucre is glabrous. This is probably what led Hall (1919) to place var. graveolens in the green forms. Nesom & Baird (1993) divide the varieties into two groups they recognize as subspecies “… previously recognized and informally referred to as the 'gray forms' and the 'green forms …” by Hall (1919)

Below is the list, with a few added comments comparing the list to the list of Nesom & Baird (1993).

The gray forms

  • bernardinus, listed as both a gray and a green form by Hall & Goodspeed, N&B93 – gray form only.
  • Bigelovii
  • frigidus, = Ericameria nauseosa var. nauseosa – a gray form.
  • glareosus
  • gnaphalodes, = Ericameria nauseosa var. hololeuca – a gray form.
  • hololeucus
  • latisquameus
  • nauseosus, s. str.
  • occidentalis, listed as both gray and green form, syn: C. californicus occidentalis, = Ericameria nauseosa var. speciosa – a gray form.
  • plattensis, = E. nauseosa var. speciosa – a gray form.
  • salicifolius
  • speciosus

    Nesom & Baird (1993) will add five more gray forms:

  • iridis L. C. Anderson
  • nana Cronquist
  • psilocarpa M. E. Jones
  • texensis L. C. Anderson
  • washoensis L. C. Anderson

The green forms

  • bernardinus listed as both gray and green form here, a gray form per N&B93.
  • californicus, = E. nauseosa var. speciosa – a gray form.
  • ceruminosus
  • consimilis, = E. nauseosa var. oreophila
  • graveolens, listed by N&B93 as a gray form.
  • junceus
  • leiospermus
  • mohavensis
  • occidentalis, listed as both gray and green form here, syn: C. californicus occidentalis, = Ericameria nauseosa var. speciosa – a gray form.
  • oreophilus
  • pinifolius, = E. nauseosa var. oreophila
  • viridulus, = E. nauseosa – a gray form.

    Nesom & Baird (1993) will add the following green forms:

  • arenaria L. C. Anderson
  • nitida L. C. Anderson
  • turninata M. E. Jones

This is Hall's (1919) description of Chrysothamnus nauseosus (Pall.) Britt. in the strict sense. This would also then be the description of variety nauseosus as we typically lay out infraspecific names today. Hall (1919) describes the plant as “permanently white-tomentose throughout” and notes the “bracts … white-wooly …” Contrast this with Hall's (1919) description of variety graveolens, below. 1. Chrysothamnus nauseosus (Pall.) Britt. (sensu strictu) in Britt and Br., Ill. Fl., vol. 3, p. 326, 1898.
Chrysocoma nauseosa Pall., in Pursh. Fl., vol. 2. p. 517, 1814.
Chrysothamnus speciosus albicaulis Nutt., Trans. Am. Philos. Soe., ser. 2. vol. 7, p. 324, 1841.
Bigelovia graveolens albicaulis Gray, Proc. Am. Acad., vol. 8. p. 645, 1873.

Shrub 5 to 10 dm. high, with numerous erect or ascending twigs, leafy to the top, permanently white-tomentose throughout; twigs not evidently striate: leaves narrowly linear, 3 to 6 cm. long, 0.5 to 1.5 mm. wide: inflorescence a rather loose round-topped cyme: involucre 7 to 8 mm. high; bracts mostly acute, plainly keeled, in 5 distinct vertical ranks, white-woolly but not ciliate: corolla 7.5 to 9 mm. long; tube perhaps always cobwebby with long weak hairs; lobes lanceolate, 1 to 2 mm. long.

This type form of the species is much less common than many of its varieties. It occurs from Utah to Oregon and probably north to British Columbia and Montana, inhabiting well drained soil with little or no alkali. In the typical form, as understood by the writer, the leaves are very narrow and, like the twigs, are entirely covered with a white flocculent tomentum, while the corolla-tube is conspicuiously arachnoid-pubescent. Such are specimens gathered by Leiberg in eastern Washington under no. 884 and others by Marcus E. Jones at Marysvale, Utah, under no. 5968. In northern Mono County, California, is encountered a form in which the leaves are 2 to 3 mm. wide and the inflorescence is more compact and rounded (H. M. H., no. 463), but in the pubescence of the corolla-tube and in all other characters than those mentioned it is plainly nauseosus. Nearly identical are specimens from Truckee, California (Heller, no. 7192). Another divergence is indicated by specimens with the broad leaves and other characters of the Mono and Truckee collections just cited but with a corolla-tube which is only crisp-pubescent as in most varieties. A recognition of these forms would lead only to confusion since further field studies would doubtless reveal still other divisions that might be made. They are therefore retained in this paper as only trivial variants of nauseosus. C. orthophyllus Greene, Pitt., vol. 5, p. 62, 1902, known only from Plumas County, California, is described as less than a foot high and with the tips of the corolla-lobes as well as the tube long-villous.

Hall (1919) describes the twigs as “… yellowish green to nearly white, more or less striate, the tomentum compact and smooth …” and states clearly that “… involucre [is] glabrous …” This fairly clearly places variety graveolens in the green forms of C. nauseosus. 14. Chrysothamnus nauseosus var. graveolens (Nutt.) Piper. Contr. U. S. Nat. Herb., vol. 11, p. 559, 1906.
Chrysocoma graveolens Nutt., Gen., vol. 2, p. 136, 1818.
Bigelovia graveolens glabrata Gray. Proc. Am. Acad., vol. 8, p. 645, 1873.

Shrub robust, leafy to summit: twigs yellowish green to nearly white, more or less striate, the tomentum compact and smooth: leaves broadly linear, 1 to 3 min. wide, mostly 3- or 5-nerved, impunctate, smooth and green but often slightly tomentulose, especially beneath: inflorescence a round or flat-topped cyme, fastigiate, the heads crowded: involucre 6 to 9 mm. high, glabrous: corolla 6 to 9 (rarely 10) mm. long; lobes 0.5 to 1 or rarely 1.6 mm. long, erect.

There can be little doubt that the original of Nuttall's Chrysocoma graveolens is the plant here described, for in the brief description are mentioned the linear, three-nerved, smooth leaves; the corymbosely fastigiate and crowded "flowers"; and the smooth, five-flowered, angular "calix." This is the common form in the easterly part of the range of the genus, especially in Wyoming, Colorado, and northern New Mexico. C. virens Greene, Pitt., vol. 5, p. 61, 1902, apparently is not to be retained even in the most subordinate rank. From the description it seems to be very near to graveolens but it is perhaps greener, the involucre only one-half as long as the flowers, and the bracts somewhat triangular. These characters are all extremely variable. Although the writer has searched for it at the type locality (Cañon City, Colorado) and in surrounding districts, no specimens were found that could be satisfactorily separated from graveolens. C. laetevirens Greene, i.e., described from material gathered at Grand Junction, Colorado, has been studied at its type locality. Apparently there is no reason for considering it more than a light-green form or state of graveolens.

  For a more complete review of the topic of American rubber, see Finlay (2010).
  … as a phreatophyte …
  … patalability of various varieties of rabbitbrush …
  … Symposium on the Biology of Artemisia and Chrysothamnus
Welch, et al. (1993), in their “Utah Flora,” 2nd edition, list our species as Chrysothamnus nauseosus (Pallas) Britt. var. glabratus (Gray) Cronq. Var. glabratus (Gray) Cronq. Glabrate rabbitbrush. [Bigelovia graveolens var. glabrata Gray; C. nauseosus ssp. graveolens (Gray) Piper; C. nauseosus var. graveolens (Gray) Hall; C. oreophilus A. Nels.]. Desert willow-baccharis, willow-cottonwood, greasewood-tamarix, sagebrush, shadscale, mountain brush, and ponderosa pine communities at 750 to 2475 m in Iron, Piute, Sanpete, Sevier, Summit, Utah, Wasatch, and Washington counties, and in all counties east of those; Idaho to North Dakota, south to Arizona, and New Mexico; 113 (xxiii).

Note: The two numbers following the entry indicate that there were 113 specimens seen during the study and that 23 of those were made by the author(s) of the group.

  Nesom & Baird … were the guys who finally bit the bullet and proposed to move the Chrysothamnus Section nauseosi to Ericameria.
  Ericameria nauseosa (Pallas ex Pursh) Neson & Baird, comb. nov. Basionym: Chrysocoma nauseosa Pallas ex Pursh, Fl. Amer. Sept. 2:517. 1814. Chrysothamnus nauseosus (Pallas ex Pursh) Britt. in Britt. & Brown, Illustr. Fl. 3:326. 1898.
Nesom & Baird (1993) formalize the recognition of “gray forms” and “green forms” previously informally recognized by Hall (1919) by dividing the varieties into two subspecies: Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird subsp. nauseosa and Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird subsp. consimilis (E. Greene) Nesom & Baird.

Variety graveolens is treated as a gray form by Nesom & Baird (1993) but as a green form by Hall (1919). Reading Hall's (1919) descriptions of the gray and green forms, variety graveolens seems to fit better into the green forms.

Nesom & Baird (1993) persist in referring to the rubber in C. nauseosus as latex, whereas Hall & Goodspeed (1919) pointed out that it is a non-latex rubber.

Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird subsp. nauseosa.

Including the following varieties (the gray forms):

  • bernardina, could be either a gray or a green form (Hall, 1919)
  • bigelovii,
  • glabrata, = var. graveolens (Nutt.) Reveal & Schuyler. treated as a green form by Hall (1919)
  • glareosa,
  • hololeuca,
  • iridis, new, not in Hall (1919).
  • latisquamea,
  • nana, new, not in Hall (1919).
  • nauseosa,
  • psilocarpa, new, not in Hall (1919).
  • salicifolia,
  • speciosa,
  • texensis, new, not in Hall (1919).
  • washoensis, new, not in Hall (1919).

Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird subsp. consimilis (E. Greene) Nesom & Baird, comb. nov. BASIONYM: Chrysothamnus consimilis E. Greene, Pittonia 5:60. 1902. Chrysothamnus nauseosus (Pallas ex Pursh) Britt. subsp. consimilis (E. Greene) Hall & Clements, Carnegie Inst. Washington Publ. 326:215. 1923.

Including the following varieties (the green forms):

  • arenaria,
  • arta, = var. oreophila (A. Nelson) Nesom & Baird, comb. nov. Phytologia 78:1, p. 63. 1995. in Hall (1919) as var. pinifolius.
  • ceruminosa,
  • juncea,
  • leiosperma,
  • mohavensis,
  • nitida, new, not in Hall (1919).
  • turbinata, new, not in Hall (1919).
It is unclear why Nesom & Baird chose to use Bigelovia graveolens Nutt. Var. glabrata A. Gray as the basionym for this new proposed name rather than Chrysocoma graveolens Nuttall.

One problem with this is that Gray, hisself, (1873) lists only a Linosyris graveolens var. glabrata Engelm., for which publication data cannot be found.

6. Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird var. glabrata (A. Gray) Nesom & Baird, comb. Nov. BASIONYM: Bigelovia graveolens Nutt. Var. glabrata A. Gray, Proc. Amer. Acad. Arts 8:645. 1873.

Chrysothamnus nauseosus (Pallas ex Pursh) Britt. Subsp. graveolens (Nutt.) Hall & Clements, Carnegie Inst. Washington Publ. 326:214. 1923.

  15. Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird var. nauseosa Basionym: Chrysothamnus nauseosus (Pallas ex Pursh) Britt. Subsp. nauseosus
  Anderson (1995) …
  Nesom & Baird (1995) …
  Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird var. oreophila (A. Nelson) Nesom & Baird, comb. nov. BASIONYM: Chrysothamnus oreophilus A. Nelson, Bot. Gaz. (Crawfordsville) 28:375. 1899. Chrysothamnus oreophilus A. Nelson var. oreophilus A. Nelson (1912, autonymic, see below). Chrysothamnus nauseosus (Pallas ex Pursh) Britt. var. oreophilus (A. Nelson) H.M. Hall, Univ. Calif. Pub. Bot. 7:175. 1919.

Chrysothamnus oreophilus A. Nelson var. artus A. Nelson, Bot. Gaz. (Crawfordsville) 54:413. 1912. Chrysothamnus nauseosus (Pallas ex Pursh) Britt. var. artus (A. Nelson) Cronquist, Vasc. Pl Pacific Northw. 5:129. 1955. Ericameria nauseosa (Pallas ex Pursh) Nesom & Baird var. arta (A. Nelson) Nesom & Baird, Phytologia 75:85. 1993. (comb. illeg.).

Chrysothamnus consimilis E. Greene, Pittonia 5:63. 1902. Chrysothamnus nauseosus (Pallas ex Pursh) Britt. var. consimilis (E. Greene) H.M. Hall, Univ. Calif. Pub. Bot. 7:176. 1919.

  Reveal, Moulton, and Schuyler (1999) proposed Ericameria nauseosa (Pall. ex Pursh) G. L. Nesom & Baird var. graveolens (Nutt.) Reveal & Schuyler, comb. et stat. nov. based on Chrysocoma graveolens Nutt. (Gen. N. Amer. P1. 2: 136. 1818) and the autonym Bigelovia graveolens (Nutt.) A. Gray var. glabrata A. Gray (in Proc. Amer. Acad. Arts 8: 645. 1873) and in their footnote 3 review their disposition of var. glabrata:
Neson & Baird incorrected (sic) proposed E. nauseosa var. glabrata (A. Gray) G. L. Nesom & Baird (in Phytologia 75: 86. 1993) for the above taxon. They corrected one of their nomenclatural errors subsequently (in Phytologia 78: 61065. 1995), but they failed to correct the above name as now required by the International Code of Botanical Nomenclature (Greuter et al., 1994)
Original Text
The DNA-based phylogenetic hypotheses presented here support the recognition of Ericameria as a lineage distinct from both Chrysothamnus and Xylothamia. Also, the treatment of Ericameria to include the four species of Chrysothamnus (C. nauseosa, C. paniculatis, C. parryi and C. teretifolius) transferred to that genus ...
  Established concepts of Chrysothamnus have been primarily based on morphological similarity or on molecular studies employing only exemplar taxa. Those investigations and treatments conceptualized Chrysothamnus as a single evolutionary unit with affinity for Ericameria, Petradoria, and Stenotus among other taxa. The hypotheses of relationship presented here are based on nuclear ribosomal 3' ETS and ITS data that were analyzed using several optimality criteria. The results indicate that Chrysothamnus as traditionally perceived is polyphyletic, with species placed in four well-supported lineages. Three of the four clades also contain taxa from other genera. Seven species of Chrysothamnus along with Acamptopappus, Amphipappus, Hesperodoria scopulorum, Tonestus lyallii, and Vanclevea constitute one clade, while four species aggregate in another clade that includes Hesperodoria salicina, Tonestus microcephalus, and T. peirsonii. A third lineage consists of Chrysothamnus gramineus and appears distantly related to any other Chrysothamnus. Finally, four species of Chrysothamnus recently transferred to Ericameria are strongly supported within the Ericameria lineage. Stenotus and Tonestus as traditionally circumscribed are not supported by the molecular data. Instead, the generitype of each is aligned with taxa other than species presently included within the same genus. The results of this investigation indicate that some of the morphological features used to delimit these genera may be the product of convergence, thus diminishing their value for phylogenetic reconstruction. , but otherwise locked behind a paywall.




Literature Cited

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Date and time this article was prepared: 5/26/2021 8:42:05 PM