Astragalus purshii |
Astragalus curvicarpus |
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Pursh's milkvetch, woollypod milkvetch |
curvepod milkvetch |
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Habit | Plants perennial, acaulescent to shortly caulescent, densely villous to villous-tomentose, hairs basifixed. | Plants perennial, caulescent, strigillose to villosulous or glabrate, hairs basifixed. |
Stems | prostrate, loosely to densely tufted, 0–20 cm. |
several–numerous, decumbent to ascending, 15–50 cm. |
Leaves | 1–12(17) cm; leaflets (3)5–17(21), elliptic to oblanceolate, 2–14(20) × 1–7 mm; tips obtuse to acute; surfaces densely villous; stipules 2.5–15 mm; free. |
2.5–9 cm; leaflets (9)11–21(25), obovate-cuneate, oblong-ovate or elliptic to broadly oblanceolate; (7)9–19(21) × 2–9 mm; tips retuse or truncate to obtuse; surfaces strigose to glabrescent or glabrous; stipules 1–5 mm; free. |
Inflorescences | racemes or subumbels, 1–12-flowered; peduncles 1–14 cm; bracts 4–9 mm; pedicels 2–4.3 mm; bracteoles 0–2. |
racemes (5)10–25(35)-flowered; peduncles 4–15 cm; bracts 0.7–2.5 mm; pedicels 1–3.5 mm; bracteoles 0. |
Flowers | ascending at anthesis; calyces 5.5–16(19) mm, often purple, villous-pilose with white or mixed white and black hairs; tubes 8.5–12.5 mm; teeth subulate, 2.2–6 mm; corollas 19–27 mm; whitish to ochroleucous or pink-purple; ovules 14–40(46). |
nodding at anthesis; calyces gibbous-saccate or gibbous-truncate at bases, 6.1–13.6 mm, villosulous or strigose with white or black hairs or a mixture; tubes 5.4–12 mm; teeth triangular, 0.4–2.3 mm; corollas 13.6–21 mm, white, ochroleucous, or lemon yellow; ovules 14–25. |
Fruits | unilocular, ascending, obliquely ovoid, usually curved, obcompressed, scarcely to deeply sulcate; (7)13–27(30) × 3.5–11 mm, densely white to tawny tomentose or densely villous; hairs nearly always concealing valve surfaces; valves coriaceous, sessile or on gynophores 0–1.6 mm. |
unilocular, pendulous, narrowly oblong, crescentic, hamate, falcate or coiled through 1.5 spirals, strongly laterally compressed, bicarinate, 14–35 × 2.7–4.5 mm; cross reticulate, villosulous, strigillose, glabrate, or glabrous; valves stiffly papery or thinly coriaceous; stipes 6–20 mm. |
Astragalus purshii |
Astragalus curvicarpus |
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Distribution | ||
Discussion | Western North America. ~8 varieties; 4 varieties treated in Flora. Throughout western North America, particularly in the Intermountain Region, this is a low, tufted milkvetch with white or gray villous hairs and pods resembling balls of cotton. Barneby (1964) stated, “Attempts to devise a practical key to the varieties of A. purshii are never wholly successful.” Variety ophiogenes, the Snake River milkvetch, a native of Idaho, has been reported from Malheur County, but this is apparently based on misidentifications of A. purshii var. lagopinus. Variety ophiogenes has 3–11-flowered racemes and 9–17 leaflets. |
3 varieties. |
Source | Flora of Oregon, volume 2, page 671 Richard Halse |
Flora of Oregon, volume 2, page 662 Richard Halse |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Astragalus purshii var. ophiogenes | |
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