Astragalus nutans
Rev. N.-Amer. Astragalus, 108. 1923.
Plants annual, biennial, or perennial (short-lived), 6–15 cm, strigulose; from superficial caudex; taproot slender. Stems single, erect or prostrate to ascending, strigulose. Leaves (2–)3–8 cm; stipules distinct, 1–4 mm, papery; leaflets 7–13, blades broadly or narrowly elliptic or oblanceolate, (3–)5–15 mm, apex obtuse, shallowly emarginate, or subacute, surfaces strigulose, sometimes glabrescent adaxially. Peduncles ascending, 2–5 cm. Racemes 6–10-flowered, flowers loosely ascending or in age declined; axis (1–)1.5–3.5(–4) cm in fruit; bracts 1–2 mm; bracteoles 0–2, minute when present. Pedicels 1–2 mm. Flowers 7.8–10.4 mm; calyx often purplish, campanulate, 4–4.6 mm, strigulose, tube 2.5–3.2 mm, lobes subulate, 1.2–2 mm; corolla pink-purple; banner recurved through 90°; keel 5.9–6.6 mm, apex blunt. Legumes horizontal or declined, stramineous, straight or slightly incurved, plumply ovoid or broadly oblong-ellipsoid, bladdery-inflated, subterete, (13–)15–25 × 11–15 mm, thin becoming papery-membranous, translucent, somewhat lustrous, sparsely strigulose, hairs straight, appressed; seed-bearing flange 1–2.5 mm wide; gynophore to 2 mm. Seeds 19–24. 2n = 22.
Phenology: Flowering Mar–Jun.
Habitat: Sandy flats and stony washes in the foothills of desert mountains, with Larrea or Yucca brevifolia.
Elevation: 400–2000 m.
Distribution
Calif.
Discussion
Astragalus nutans is known from the eastern Mojave and extreme northern Colorado deserts of San Bernardino and Riverside counties. R. C. Barneby (1964) postulated a close relationship to A. gilmanii.
Selected References
None.