Astragalus detritalis
Plants dwarf, tuft-forming, 0.5–8 cm, densely silver-strigulose or -strigose; from branched caudex, branches with thatch of persistent stipules and leaf-bases. Stems very short or ± absent, forming depressed tufts. Leaves reduced to phyllodia or palmately trifoliolate or odd-pinnate distally, 0.5–8 cm; stipules mostly connate-sheathing, 3–10 mm, scarious; leaflets 0(or 3–7), blades narrowly oblanceolate to linear, 3–30 mm, apex spinulose, surfaces strigose; phyllodia not differentiated into petiole and blade. Peduncles erect or incurved-ascending, ascending or decumbent in fruit, 1–9 cm. Racemes densely 2–8-flowered; axis 0.9–3.8 cm in fruit; bracts 2.5–7 mm; bracteoles 0–2. Pedicels 0.5–2.5 mm. Flowers 12–20 mm; calyx 5–9.6 mm, strigose, tube 3.1–5.4 mm, lobes subulate, 1.6–4.7 mm; corolla pink-purple; banner recurved through 45°; keel (8.4–)9.4–12.8(–13.4) mm. Legumes erect, green, usually also red-mottled, becoming stramineous, straight or curved, linear-oblong, laterally compressed, 15–38 × 2–3.5 mm, papery, strigose; sessile. Seeds 15–24.
Phenology: Flowering late Apr–Jun.
Habitat: Pinyon-juniper and shadscale, greasebush, black sagebrush, galleta, wildrye, Ephedra and other mixed desert shrub communities, on Duchesne, Green, and Uinta river formations, on pedimental Quaternary gravel.
Elevation: 1500–2800 m.
Distribution
Colo., Utah.
Discussion
Astragalus detritalis is restricted to the Uinta Basin in northeastern Utah and adjacent Colorado. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.
Selected References
None.