Astragalus tiehmii
Brittonia 36: 169, fig. 1. 1984.
Plants 4–15+ cm, 1–3.5(–4.5) dm wide, gray-pilosulous; from branched caudex. Stems prostrate, gray-pilosulous. Leaves 0.8–2.6 cm; stipules distinct, 1–2.5 mm; leaflets 7 or 9, blades folded, obovate-cuneate, 2–6 mm, apex emarginate, surfaces pilosulous. Peduncles 0.3–0.7 cm, often paired at a node. Racemes (3 or)4–7(or 8)-flowered, flowers declined; axis 0.3–1 cm in fruit; bracts 0.5–1.2 mm; bracteoles 0. Pedicels 0.8–1.8 mm. Flowers 4.8–5.3 mm; calyx obconic-campanulate, 3.6–4.2 mm, white-pilosulous, tube 1.3–1.8 mm, lobes slenderly subulate, 1.3–1.8 mm; corolla whitish, banner tinged or veins faint lilac; banner recurved through 90°; keel 3.3–3.6 mm, apex obtuse. Legumes spreading-declined, lunately ellipsoid-obovoid, laterally compressed, somewhat depressed but not grooved dorsally, lateral faces with shallow longitudinal groove, 4.5–5 × 2–2.5 mm, unilocular, sparsely pilosulous. Seeds 2 or 3.
Phenology: Flowering Jun–Jul.
Habitat: White volcanic ash deposits.
Elevation: 1600–1800 m.
Distribution
Nev.
Discussion
Astragalus tiehmii is diminutive in all its parts, appearing as a small A. pulsiferae, but it is essentially similar, and probably more closely allied, to A. tegetarioides. R. C. Barneby (1984), however, considered its kinship with the former. It is known from the western side of the Black Rock Desert in Washoe County.
Selected References
None.