Eriogonum brachyanthum |
Eriogonum abertianum |
|
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short-flower buckwheat, short-flower wild buckwheat, yellow buckwheat |
Abert's buckwheat, Abert's wild buckwheat |
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Habit | Herbs, spreading, (0.5–)1–3 dm, glabrous, greenish. | Herbs, erect or spreading, annual, 0.5–6(–7) dm, hirsute, greenish, grayish, tawny, or reddish. |
Stems | aerial flowering stems erect, 0.3–0.8 dm, glabrous. |
caudex absent; aerial flowering stems prostrate to erect, solid, not fistulose, 0.1–1 dm, appressed-hirsute. |
Leaves | basal; petiole 0.5–3 cm, tomentose; blade ovate to rounded, 0.5–2 × 0.5–2 cm, densely white-tomentose on both surfaces, rarely glabrate and grayish or greenish adaxially. |
basal and cauline; basal: petiole 0.5–6 cm, villous to hoary, blade oblong to obovate, 1–4 × 1–3 cm, villous to hoary-tomentose and greenish, tawny, or reddish on both surfaces, margins plane, occasionally crenulate; cauline sessile, blade linear, lanceolate, or narrowly obovate, 1–4 × 0.3–2 cm, similar to basal blade. |
Inflorescences | cymose, occasionally distally uniparous due to suppression of secondary branches, usually diffuse, 5–25 × 5–30 cm; branches glabrous; bracts 0.5–2 × 0.5–2 mm. |
cymose, open to diffuse, 5–40(–60) × 5–50 cm; branches hirsute; bracts 3–6, semileaflike, 2–10 × 1–3 mm. |
Peduncles | absent. |
ascending to erect, mostly straight, slender, 0.5–6 cm, villous to hoary-tomentose. |
Involucres | somewhat appressed to branches, turbinate, 1–1.2 × 0.4–0.6 mm, glabrous; teeth 5, erect, 0.2–0.3 mm. |
broadly campanulate, 2–3 × 2–3 mm, villous-canescent; teeth 5, lobelike, usually reflexed, 4–6 mm. |
Flowers | 0.6–0.8(–1) mm; perianth yellow or pale yellowish, rarely whitish, glabrous; tepals slightly dimorphic, those of outer whorl oblong to oblong-obovate, those of inner whorl narrowly oblong; stamens included, 0.5–0.8 mm; filaments pilose proximally. |
3–4.5 mm; perianth white to pale yellow in early anthesis, becoming reddish or rose, glabrous; tepals dimorphic, those of outer whorl orbiculate-cordate, those of inner whorl lanceolate to spatulate; stamens mostly exserted, 1.5–3.5 mm; filaments mostly pilose proximally. |
Achenes | dark brown, 3-gonous, 0.8–1 mm. |
brown to dark brown, lenticular, 0.6–1 mm, glabrous. |
2n | = 40. |
|
Eriogonum brachyanthum |
Eriogonum abertianum |
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Phenology | Flowering Apr–Nov. | Flowering year-round. |
Habitat | Sandy to gravelly flats, washes, and slopes, saltbush, greasewood, and sagebrush communities, pinyon-juniper and montane conifer woodlands | Sandy, gravelly, or clayey flats, washes, and slopes, mixed grassland, saltbush, greasewood, creosote bush, blackbrush, and manzanita communities, oak and conifer woodlands |
Elevation | 600-2300 m (2000-7500 ft) | 400-2500 m (1300-8200 ft) |
Distribution |
CA; NV; OR
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AZ; NM; TX; Mexico (Coahuila, Chihuahua, Sonora, San Luis Potosí)
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Discussion | Eriogonum brachyanthum basically is a species of the Mojave Desert, extending northward in eastern California (Inyo, Kern, Los Angeles, Mono, Riverside, and San Bernardino counties) and along the Lahontan Trough of Nevada (Churchill, Esmeralda, Eureka, Humboldt, Lander, Lyon, Mineral, Nye, Pershing, and Washoe counties) to just north of Denio in Harney County, Oregon. It is common to abundant and even locally weedy in the northern Mojave Desert. Elsewhere it is less common and much more widely scattered. It often is found with other annual wild buckwheats forming dense patches (especially along highways) composed of several (up to seven in places) species, and care must be taken to sort them properly when making herbarium specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eriogonum abertianum is widespread and common to abundant or even locally weedy. It is basically a species of the Chihuahuan and Sonoran deserts, ranging from San Luis Potosí and Sonora in northern Mexico to western Texas and much of New Mexico and Arizona. This species is exceedingly variable and can be differentiated into several geographic and seasonal phases (C. C. Baskin et al. 1993; G. A. Fox 1989, 1990, 1990b). Variety abertianum (including E. pinetorum) is a more northern and western, summer- and fall-flowering expression, with an erect habit and a cymose-paniculate inflorescence when the plants are in fruit. A vernal phase (var. villosum) of this northern form occurs throughout much of the same range (mainly Arizona, New Mexico, and the Sonoran Desert of Mexico). It is a hairier and more spreading expression, with elongated inflorescence branches bearing more floriferous involucres. Variety ruberrimum (including E. cyclosepalum) is the more southern, summer- to fall-flowering expression (mainly New Mexico, Texas, and the Chihuahuan Desert of Mexico) with a prostrate to spreading, compact habit and a racemose inflorescence at full maturity. There is a vernal expression of this as well; it differs from the vernal form of var. abertianum in having longer peduncles. There are no sharp morphologic or geographic boundaries for any of these expressions, and while the fruiting extremes are clearly distinguishable, far too many specimens are impossible to place satisfactorily. The Navajo (Diné) people use these plants as a lotion for both themselves and their horses (P. A. Vestal 1952). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 426. | FNA vol. 5, p. 407. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oregonium | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma |
Sibling taxa | ||
Synonyms | E. baileyi var. brachyanthum, E. vimineum var. brachyanthum | E. abertianum var. cyclosepalum, E. abertianum var. lappulaceum, E. abertianum var. neomexicanum, E. abertianum subsp. pinetorum, E. abertianum var. ruberrimum, E. abertianum var. villosum, E. cyclosepalum, E. pinetorum |
Name authority | Coville: Contr. U.S. Natl. Herb. 4: 185. (1893) | Torrey: in W. H. Emory, Not. Milit. Reconn., 150. (1848) |
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