Astragalus paysonii
Leafl. W. Bot. 4: 60. 1944.
Plants somewhat slender, 20–45(–65) cm, glabrous or sparsely strigulose; from superficial or slightly subterranean caudex. Stems decumbent to ascending, glabrous or sparsely strigulose. Leaves 4–9.5 cm; stipules 2–5 mm, submembranous becoming papery; leaflets 7–15(or 17), blades ovate, ovate-oblong, or obovate-cuneate, 5–20 mm, apex retuse, surfaces sparsely strigulose abaxially, glabrous adaxially. Peduncles incurved-ascending, 3–9 cm. Racemes 5–20-flowered; axis 1–4.5 cm in fruit; bracts 0.8–2 mm; bracteoles 0. Pedicels 0.5–1.2 mm. Flowers 7–9 mm; calyx 3.2–4.6 mm, strigulose, tube 2–2.9 mm, lobes subulate, 1–1.7 mm; corolla whitish, sometimes faintly tinged lilac; banner recurved through 45°; keel 4.8–5.5 mm. Legumes pendulous, stramineous or brown, lunate, linear-ellipsoid, 3-sided compressed, 10–17 × 2.5–3.5 mm, papery, glabrous; septum 1.3–2 mm wide; stipe 1–1.5 mm. Seeds 8–10.
Phenology: Flowering Jun–Oct.
Habitat: Open aspen, lodgepole pine, and Douglas-fir timber forests, burned-over or clear-cut forests, roadcuts, on decomposed granite.
Elevation: 1700–3000 m.
Discussion
Despite the disjunction of Astragalus paysonii in north-central Idaho and western Wyoming, plants from the two areas are essentially the same morphologically.
Selected References
None.