Astragalus spatulatus

Plants tuft- or mat-forming, 1.5–9(–12) cm, densely strigulose; from branched caudex. Stems obscured by marcescent leaf bases and stipules. Leaves mostly reduced to phyllodia, few with leaflets, 0.8–10 cm; stipules connate-sheathing throughout, 2–7 mm, papery-scarious; leaflets 0(or 3–5), blades (phyllodia) oblanceolate to linear, 4–30 mm, apex acute, mucronate, or spinulose, surfaces strigose; terminal leaflet often confluent with rachis. Peduncles erect or ascending, outer ones often prostrate in fruit, 0.4–9 cm. Racemes densely 1–11-flowered; axis 0.2–3.5 cm in fruit; bracts 0.5–4 mm; bracteoles 0. Pedicels 0.3–1.7 mm. Flowers 5.7–9.5 mm; calyx 2.6–5 mm, strigose, tube 1.9–3.4 mm, lobes subulate, 0.5–2.5 mm; corolla pink purplish to ochroleucous or whitish; banner recurved through 45°; keel 4–6 mm. Legumes erect, pale green tinged purple, with red-mottle, becoming brown or stramineous, straight or slightly curved, lanceoloid to lanceoloid-oblong, 2-sided, laterally compressed, 4–13 × 1.5–3.3 mm, papery, usually strigose, rarely glabrous; sessile. Seeds 4–12. 2n = 24.

Phenology: Flowering May–Jul.
Habitat: Pinyon-juniper, sagebrush, and mountain brush communities, exposed ridges.
Elevation: 600–2700 m.

Alta., Sask., Colo., Idaho, Kans., Mont., Nebr., N.Dak., S.Dak., Utah, Wyo.

Discussion

The nomenclature of Astragalus spatulatus was confused from the start with three epithets proposed by T. Nuttall in J. Torrey and A. Gray (1838–1843) within Homalobus that were previously used in Astragalus and, as a result, not available. The habit of A. spatulatus varies from a low cushion, with flowers borne barely above the very short leaves, to taller plants with elongate leaves and flowers borne well above the ground. The extremes are distinctive but are connected by a series of intermediates.

Selected References

None.

Lower Taxa