Eriogonum flavum |
Eriogonum flavum var. piperi |
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alpine golden buckwheat, alpine golden wild buckwheat, yellow buckwheat |
Piper's buckwheat, Piper's golden buckwheat, Piper's wild buckwheat, yellow buckwheat |
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Habit | Herbs, matted, 0.2–4 × 1–10 dm, tomentose to floccose. | Plants loose to compact mats, 1–6 dm wide. | ||||||||
Stems | caudex absent or spreading; aerial flowering stems erect or nearly so, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, (0.1–)0.5–2(–3) dm, tomentose to floccose. |
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Aerial flowering stems | mostly erect, (0.5–)1–2(–3) dm. |
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Leaves | basal, occasionally in rosettes; petiole 0.5–4 cm, tomentose to floccose; blade linear-oblanceolate to oblong or elliptic, 1–7(–9) × (0.3–)0.5–1.5 cm, densely whitish- or grayish-tomentose abaxially, mostly tomentose to floccose or glabrous and green adaxially, margins entire, plane. |
blades linear-oblanceolate to oblong or narrowly elliptic, 2–7(–9) × 0.3–0.8(–1) cm, densely tomentose abaxially, tomentose to floccose or glabrous and greenish adaxially. |
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Inflorescences | subcapitate or umbellate, 0.5–3(–5) × 0.3–2.5(–3) dm; branches tomentose to floccose; bracts 4–6, leaflike to semileaflike at proximal node, 0.5–2 × 0.2–0.5 cm, sometimes absent immediately below involucre. |
subcapitate to umbellate; branches 0.2–1 cm. |
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Involucres | 1 per node, turbinate to campanulate, 3–9 × 2–5 mm, tomentose to floccose; teeth 5–8, erect, 0.2–1 mm. |
usually turbinate, 4–9 mm. |
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Flowers | 3–7 mm, including 0.2–1.5 mm stipelike base; perianth pale to bright yellow, densely pubescent abaxially; tepals monomorphic, oblong; stamens exserted, 3–6 mm; filaments pilose proximally. |
(4–)5–7 mm, including 1–1.5 mm stipelike base; perianth pale to bright yellow. |
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Achenes | light brown to brown, 3–5 mm, glabrous except for sparsely pubescent beak. |
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2n | = 76, 80. |
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Eriogonum flavum |
Eriogonum flavum var. piperi |
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Phenology | Flowering Jun–Sep. | |||||||||
Habitat | Sandy to gravelly flats and slopes in mixed grassland and sagebrush communities, and in montane to subalpine conifer woodlands | |||||||||
Elevation | (700-)1200-2800(-3200) m ((2300-)3900-9200(-10500) ft) | |||||||||
Distribution |
AK; CO; ID; MT; ND; NE; OR; SD; WA; WY; AB; BC; MB; SK; YT
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ID; MT; OR; WA; WY; AB; BC |
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Discussion | Varieties 3 (3 in the flora). Eriogonum flavum approaches E. arcuatum morphologically in southeastern Wyoming, and a clear distinction is not always possible when the plants are immature or the herbarium material is poor. Variety polyphyllum, as traditionally circumscribed, is an alpine phase of both var. flavum and var. piperi; it is encountered infrequently in scattered range in the high mountains of southwestern Montana and northwestern Wyoming. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Variety piperi is the common and widespread phase of the species, found mainly west of the Continental Divide in southern Alberta, southern British Columbia, eastern Washington, northern Idaho, and western Montana south into northeastern Oregon and northwestern Wyoming. It is only slightly variable, the major exception being depauperate individuals at high elevations in harsh exposures; these have been recognized by some as var. polyphyllum. The length of the stipelike base shortens from west to east, but only rarely are individuals in Montana troublesome to place either here or in var. flavum. The plants do well in cultivation and are now widely available. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 5, p. 371. | FNA vol. 5, p. 372. | ||||||||
Parent taxa | Polygonaceae > subfam. Eriogonoideae > Eriogonum | Polygonaceae > subfam. Eriogonoideae > Eriogonum > Eriogonum flavum | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | E. flavum var. polyphyllum, E. polyphyllum | E. piperi, E. flavum subsp. piperi | ||||||||
Name authority | Nuttall: Cat. Pl. Upper Louisiana, no. 34. (1813) | (Greene) M. E. Jones: Contr. W. Bot. 11: 7. (1903) | ||||||||
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