Plants stout, clump-forming, 10–30 cm, sparsely strigulose; from subterranean caudex. Stems decumbent to ascending or erect, sparsely strigulose. Leaves 2.5–9 cm; stipules connate-sheathing and papery at proximal nodes, connate or distinct and herbaceous at distal nodes, 4–13 mm; leaflets 5–13, blades linear-oblong, 10–45(–60) mm, margins flat, elevated, apex obtuse to apiculate, surfaces strigose; terminal leaflet decurrent, not jointed to rachis. Peduncles erect and incurved-ascending, 3–12 cm. Racemes 6–20-flowered, flowers ascending; axis 2–12 cm in fruit; bracts 2.5–7 mm; bracteoles 1 or 2. Pedicels 1.5–4 mm. Flowers 24–30 mm; calyx 10–14.5 mm, strigose, tube 7–10.2 × 4.5–6.2 mm, lobes subulate, 2–4.5 mm; corolla white, concolorous; keel 13.6–20.2 mm. Legumes deflexed, brown or stra­mineous, straight, oblong-ellipsoid, sub­terete becoming laterally compressed, 13–33 × 6–12 mm, fleshy becoming woody, glabrous or minutely puberulent; sessile. Seeds 20–28.

Phenology: Flowering late May–Aug.
Habitat: Saline, seleniferous soil in desert shrub and juniper-sagebrush communities.
Elevation: 1800–2200 m.

Distribution

• Generated Map
• Legacy Map

Colo., Utah, Wyo.

Discussion

Astragalus nelsonianus is known from Moffat County in Colorado, Daggett County in Utah, and Fremont, Natrona, Sweetwater, and Uinta counties in Wyoming.

The selenophyte Astragalus nelsonianus is essentially a broad-leaved, larger-flowered phase of A. pectinatus and might best be placed as a variety of that species as was proposed by M. E. Jones.

Selected References

None.

Lower Taxa

None.