Astragalus purshii |
Astragalus malacus |
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Pursh's milkvetch, woollypod milkvetch |
shaggy milkvetch |
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Habit | Plants perennial, acaulescent to shortly caulescent, densely villous to villous-tomentose, hairs basifixed. | Plants perennial, caulescent, prominently grayish hirsute to pilose, hairs basifixed. |
Stems | prostrate, loosely to densely tufted, 0–20 cm. |
several, decumbent to erect, 2–30 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. |
4–15 cm; leaflets 7–21, elliptic to obovate, 5–20(22) × 4–8(13) mm; tips obtuse; retuse or subacute, sometimes minutely apiculate; surfaces abaxially pubescent, adaxially pubescent or glabrescent; stipules 7–17 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 loosely 9–35-flowered; peduncles 4–11 cm; bracts 4–9 mm; pedicels 0.7–3 mm; bracteoles 2. |
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). |
declined at anthesis; calyces 8.6–14 mm, often purplish-tinged; hirsute with black or mixture of black and white hairs; tubes 6–10 mm; teeth subulate, 1.5–5 mm; corollas 12–19 mm; reddish purple; ovules 15–24. |
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. |
bilocular, declined, narrowly oblong or oblong-elliptic, shallowly to deeply incurved, dorsally deeply sulcate, triquetrously compressed, 18–38 × 4.5–6 mm; shaggy hirsute; valves stiffly papery; stipes 1–3 mm. |
Astragalus purshii |
Astragalus malacus |
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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. |
Sagebrush, rocky slopes. Flowering Apr–Jun. 700–1900 m. BR, ECas, Owy. CA, ID, NV. Native. |
Source | Flora of Oregon, volume 2, page 671 Richard Halse |
Flora of Oregon, volume 2, page 668 Richard Halse |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Astragalus purshii var. ophiogenes | |
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