Astragalus uncialis
Leafl. W. Bot. 3: 101, plate 1, fig. E. 1942.
Plants forming rather dwarf, compact tufts, acaulescent, 1.5–7.5 cm, silvery-strigose, hairs basifixed; from branching caudex. Stems obscured by stipules. Leaves 1.5–7.5 cm; stipules 3–6.5 mm, membranous, pallid, with green midrib; leaflets 3 or 5, blades oblanceolate, elliptic, or narrowly obovate, 5–17 mm, apex acute to subobtuse, surfaces strigose. Peduncles ascending, prostrate in fruit, 0.5–3.5 cm, mostly shorter than leaves. Racemes 1–3-flowered, flowers ascending; axis to 0.3 cm in fruit; bracts 1.5–3.5 mm; bracteoles 0 or 1. Pedicels 1.5–3 mm. Flowers 24.5–32 mm; calyx cylindric, 12–17 mm, strigulose, hairs white, sometimes also black, tube 10.2–13 mm, lobes subulate, 1.8–3.5 mm; corolla pink-purple or purple; banner recurved through 40°; keel 21.5–24.5 mm. Legumes ascending, stramineous, ± straight, obliquely lanceoloid-ellipsoid, dorsiventrally compressed, 20–35(–40) × 8–12 mm, unilocular, valves much less than 1 mm thick, thinly fleshy becoming leathery, strigulose, hairs appressed, 0.5–0.7 mm. Seeds 38–54.
Phenology: Flowering Apr–Jun.
Habitat: Shadscale, budsage, horsebrush, and sagebrush and greasewood communities.
Elevation: 1400–1900 m.
Discussion
The general aspect of Astragalus uncialis is that of a small A. newberryi, near which R. C. Barneby (1964) placed it. The main area of distribution of this Great Basin endemic seems to be on the low recessional terraces of ancient Lake Bonneville in Millard County, Utah.
Selected References
None.