Astragalus malacus

Plants somewhat coarse, 2.5–25(–30) cm, hirsute-villosulous; from superficial caudex. Stems several, erect or ascending, proximalmost internodes very short, hirsute-villosulous. Leaves 4–15 cm; stipules obscuring proximal internodes, 7–17 mm, whitish-papery at proximal nodes, thinly herbaceous at distal nodes; leaflets (7–)11–19(or 21), blades obovate, obovate-cuneate, or elliptic, 5–20 mm, apex obtuse, retuse, or subacute, surfaces hirsute-villosulous, sometimes glabrescent adaxially. Peduncles erect or incurved-ascending, sometimes reclined in fruit, 4–11 cm. Racemes 9–35-flowered, flowers declined; axis 2–10(–15) cm in fruit; bracts 4–9 mm; bracteoles 2. Pedicels 0.7–3 mm. Flowers 12–15 mm; calyx cylindric, 8.6–13(–14) mm, hirtellous, tube 7–9 mm, lobes subulate, 1.6–4(–5) mm; corolla reddish purple; keel 12.3–14.5(–16) mm. Legumes reflexed, green and suffused or dotted red, becoming stramineous, shallowly to deeply incurved, narrowly oblong or oblong-ellipsoid, 3-sided compressed, grooved dorsally, 18–38 × 4.5–6 mm, bilocular, fleshy becoming stiffly papery, shaggy-hirsute, hairs lustrous, spreading, 1–3 mm; stipe 1–3 mm. Seeds 16–24.

Phenology: Flowering later Apr–early Jun.
Habitat: Sagebrush or pinyon communities, various substrates.
Elevation: 1200–2300 m.

Calif., Idaho, Nev., Oreg.

Discussion

Astragalus malacus, although completely allopatric, is reminiscent of a coarse A. minthorniae, especially var. villosus, which it resembles in the greatly shortened proximalmost internodes obscured by stipules, similar though shorter vestiture, and in the general conformation of the plant. It differs, however, in many features, such as the deflexed or declined, three-sided compressed, dorsally grooved legumes.

D. Isely (1998) noted that the conspicuous characters of Astragalus malacus include its shaggy pilosity, long stipules, narrow, red-purple, deflexed flowers, and pilose, sulcate, bilocular, deflexed, upcurved legumes.

Selected References

None.

Lower Taxa