Eriogonum strictum |
Eriogonum abertianum |
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Blue Mountain buckwheat, strict buckwheat |
Abert's buckwheat, Abert's wild buckwheat |
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Habit | Herbs, erect, loosely to densely matted, not scapose, 1–5 × 1–10 dm, tomentose or glabrous. | Herbs, erect or spreading, annual, 0.5–6(–7) dm, hirsute, greenish, grayish, tawny, or reddish. | ||||||||||||
Stems | spreading to erect, with or without persistent leaf bases, up to 1/4 height of plant; caudex stems absent or spreading to matted; aerial flowering stems erect to spreading, slender, solid, not fistulose, 1–3 dm, tomentose or glabrous. |
caudex absent; aerial flowering stems prostrate to erect, solid, not fistulose, 0.1–1 dm, appressed-hirsute. |
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Leaves | basal, 1 per node; petiole rarely twisted or curled, 1–6 cm, mostly tomentose; blade elliptic to ovate, 0.5–2.5(–4) × (0.3–)0.5–1.5 cm, lanate, tomentose to floccose on both surfaces, sometimes sparsely tomentose to floccose and greenish or floccose to subglabrous or glabrous adaxially, 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. |
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Inflorescences | umbellate-cymose to cymose, 1–20 × 3–25 cm; branches dichotomous, tomentose to floccose or less often glabrous; bracts 3, scalelike, triangular, 1–3 mm. |
cymose, open to diffuse, 5–40(–60) × 5–50 cm; branches hirsute; bracts 3–6, semileaflike, 2–10 × 1–3 mm. |
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Peduncles | absent. |
ascending to erect, mostly straight, slender, 0.5–6 cm, villous to hoary-tomentose. |
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Involucres | 1 per node, rarely 2–5 per cluster, narrowly turbinate to turbinate-campanulate, 4–6 × 1.5–5 mm, tomentose or glabrous; teeth 5, erect, 0.5–1.3 mm. |
broadly campanulate, 2–3 × 2–3 mm, villous-canescent; teeth 5, lobelike, usually reflexed, 4–6 mm. |
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Flowers | 3–5(–6) mm; perianth yellow or white to rose or purple, glabrous; tepals connate proximally, dimorphic, those of outer whorl elliptic to nearly orbiculate, 2–3 × 2–3 mm, those of inner whorl oblanceolate to oblong, 3–4 × 1–2 mm; stamens included to slightly exserted, 2–5 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. |
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Achenes | light brown to brown, 3–3.5 mm, glabrous. |
brown to dark brown, lenticular, 0.6–1 mm, glabrous. |
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2n | = 40. |
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Eriogonum strictum |
Eriogonum abertianum |
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Phenology | Flowering year-round. | |||||||||||||
Habitat | Sandy, gravelly, or clayey flats, washes, and slopes, mixed grassland, saltbush, greasewood, creosote bush, blackbrush, and manzanita communities, oak and conifer woodlands | |||||||||||||
Elevation | 400-2500 m (1300-8200 ft) | |||||||||||||
Distribution |
CA; ID; MT; NV; OR; WA
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AZ; NM; TX; Mexico (Coahuila, Chihuahua, Sonora, San Luis Potosí)
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Discussion | Varieties 4 (4 in the flora). Eriogonum strictum, E. niveum, and E. ovalifolium form a complex of closely related species differing in leaf, inflorescence branching, and flower features. Variety proliferum appears to be the basal entity of the complex, approaching both E. niveum and E. ovalifolium var. pansum in its pubescence and branching pattern. Also, specimens of var. proliferum are sometimes difficult to differentiate from E. nudum var. oblongifolium. Careful observation, though, will permit well-made collections to be easily distributed among the individual species. An alternative taxonomy is to reduce all of the taxa to E. ovalifolium and recognize a series of subspecies and varieties. It is possible that additional study will show that E. strictum is sufficiently distinct from its tomentose to floccose counterparts to justify recognition of E. proliferum. In that case, both var. anserinum and var. greenei would be assigned to the latter species. Or, one could follow C. L. Hitchcock et al. (1955–1969, vol. 2) and recognize subsp. strictum as distinct from subsp. proliferum, with the latter consisting of varieties proliferum, anserinum, and greenei. Members of the Eriogonum strictum are food plants for the Bauer’s dotted-blue butterfly (Euphilotes baueri). (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.) |
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Key |
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Source | FNA vol. 5, p. 317. | FNA vol. 5, p. 407. | ||||||||||||
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla | Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate 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: Trans. Linn. Soc. London 17: 414. (1836) | Torrey: in W. H. Emory, Not. Milit. Reconn., 150. (1848) | ||||||||||||
Web links |