Eriogonum gordonii |
Eriogonum abertianum |
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Gordon's buckwheat, Gordon's eriogonum, Gordon's wild buckwheat |
Abert's buckwheat, Abert's wild buckwheat |
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Habit | Herbs, erect to spreading, annual, (0.5–)1–5(–7) dm, glabrous or sparsely hispid, grayish. | Herbs, erect or spreading, annual, 0.5–6(–7) dm, hirsute, greenish, grayish, tawny, or reddish. |
Stems | caudex absent; aerial flowering stems erect, solid, not fistulose, 0.5–1.5(–3) dm, glabrous or sparsely hispid. |
caudex absent; aerial flowering stems prostrate to erect, solid, not fistulose, 0.1–1 dm, appressed-hirsute. |
Leaves | basal; petiole 1–5 cm, glabrous or sparsely hirsute; blade obovate to round or reniform, 1–5 × 1–5 cm, sparsely villous to hirsute and green on both surfaces, becoming glabrous with age, margins plane. |
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, open to dense, 5–40(–50) × 5–50 cm; branches not fistulose, glabrous or sparsely hispid; bracts 3, scalelike, 0.5–2(–3) × 0.5–2.5 mm. |
cymose, open to diffuse, 5–40(–60) × 5–50 cm; branches hirsute; bracts 3–6, semileaflike, 2–10 × 1–3 mm. |
Peduncles | erect, straight, slender, 0.5–2.5(–4) cm, glabrous. |
ascending to erect, mostly straight, slender, 0.5–6 cm, villous to hoary-tomentose. |
Involucres | campanulate, 0.6–1.5 × 0.8–1.5 mm, glabrous; teeth 5, erect, 0.2–0.4 mm. |
broadly campanulate, 2–3 × 2–3 mm, villous-canescent; teeth 5, lobelike, usually reflexed, 4–6 mm. |
Flowers | 1–2.5 mm; perianth white with greenish or reddish midribs, rarely yellowish, becoming pink to rose, glabrous; tepals monomorphic, oblong to narrowly ovate; stamens included to exserted, 1–1.8 mm; filaments glabrous. |
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 | shiny light brown to brown, 3-gonous, 2–2.5 mm, glabrous. |
brown to dark brown, lenticular, 0.6–1 mm, glabrous. |
2n | = 40. |
|
Eriogonum gordonii |
Eriogonum abertianum |
|
Phenology | Flowering May–Oct. | Flowering year-round. |
Habitat | Sandy to clayey flats and slopes, saltbush, greasewood, and sagebrush communities, pinyon and/or juniper or 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 | 900-2200 m (3000-7200 ft) | 400-2500 m (1300-8200 ft) |
Distribution |
AZ; CO; NE; NM; SD; UT; WY
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AZ; NM; TX; Mexico (Coahuila, Chihuahua, Sonora, San Luis Potosí)
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Discussion | Eriogonum gordonii is common to even locally abundant throughout a range that extends in an arc from the Colorado Plateau of extreme northern Coconino and Apache counties, Arizona, and San Juan County, New Mexico, northward through the desert regions of eastern Utah and western Colorado into southwestern Wyoming, then northeastward mainly in short-grass prairie through east-central Wyoming and extreme northwestern Nebraska to South Dakota. A series of disjunct populations occurs in Fremont and Las Animas counties in Colorado. The species can be weedy in appearance but usually is absent from areas of significant disturbance, unlike other annual wild buckwheats. (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. 391. | FNA vol. 5, p. 407. |
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma |
Sibling taxa | ||
Synonyms | 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 | Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 20. (1856) | Torrey: in W. H. Emory, Not. Milit. Reconn., 150. (1848) |
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