Astragalus nyensis
Leafl. W. Bot. 7: 195. 1954.
Plants annual or winter-annual, slender, 1–28 cm, hirsutulous, hairs basifixed; taproot slender. Stems prostrate, spreading from root-crown, hirsutulous. Leaves 1–4 cm; stipules 1–2.2 mm, papery-membranous at proximal nodes, thinly herbaceous at distal nodes; leaflets 7–13, blades oblong-obovate or ovate-lanceolate, 2–7 mm, apex retuse, surfaces hirsutulous, sometimes glabrous adaxially. Peduncles 0.3–2.5(–3.8) cm. Racemes 1–4-flowered, flowers declined; axis 0–1.5(–2.3) cm in fruit; bracts 0.6–1 mm; bracteoles 0. Pedicels 0.8–1 mm. Flowers 4.2–5.4 mm; calyx 3–4 mm, hirsutulous, tube 1.6–2.3 mm, lobes lanceolate-subulate, 1.3–2 mm; corolla whitish, banner veins purple; banner recurved through 40°; keel 3.7–4.5 mm, apex bluntly deltate. Styles glabrous. Legumes dehiscent on plant, declined, stramineous or brownish, gently incurved or incurved through 0.2–0.3 spiral, linear-oblong, 3-sided compressed, 13–18 × 2.8–4.1 mm, thin becoming papery, hirsutulous, hairs curved. Seeds 12–14. 2n = 26.
Phenology: Flowering Apr–Jun.
Habitat: Calcareous desert mountains, with desert shrubs and grasses.
Elevation: 300–1700 m.
Distribution
Calif., Nev., Utah.
Discussion
Astragalus nyensis is known from extreme southeastern Inyo County in California, southern Nevada, and southwestern Utah.
Astragalus nyensis was placed among the California annual group (sect. Leptocarpi, subsect. Californici) by R. C. Barneby (1964) because of its easily disarticulated fruits. Anatomical characteristics of the fruit, and allozyme similarities, ally it with A. nuttallianus (A. Liston 1990). In addition, the overall similarity in flower structure and size also indicates a close relationship. Astragalus nyensis forms flat sprays on the ground, the prostrate stems radiating from the root-crown, quite unlike A. nuttallianus. In specimens seen, the fruits seldom are more than gently and evenly curved, not forming 1/4–1/3 circle as described by Barneby.
Selected References
None.