Herbs, perennial (seldom flow­ering first year), mat-forming or cespitose, diffuse, low, greenish gray (young growth cinereous), 0.5–1 dm (3–12 dm wide), not fleshy, ±villous to glabrate, hairs curved; woody-taprooted. Stems 1–20+, procumbent, branched, wiry, slender, leafy. Leaves irregularly pin­nate to subpalmate; stipules glandlike; subsessile to petiolate; rachis (1–)2–10(–15) mm, not or ± flattened; leaflets 3–5, blades obovate to elliptic, apex acute to obtuse, surfaces villous, hairs curved. Peduncles ascending, 3–15(–30 proximally) mm, shorter than leaves; bract 1–3-foliolate, subtending umbel. Inflorescences (1–)3–12-flowered. Flowers 4.5–8(–10) mm; calyx (3.5–)4–7 mm, tube sparsely villosulous, lobes sub­ulate, subequal; corolla yellow, reddening, usually drying dark, claws shorter than calyx tube, banner implicate-ascending, wings longer than keel; style curved, glabrous. Legumes deciduous with calyx, exserted, declined or deflexed, tawny, strongly arched, turgid, not constricted, not septate, ovoid-ellipsoid, 6–10 ×1.8–2.2 mm, leathery, apex long, tapering to curved, slender beak, indehiscent, veined, margins keeled, rugose, strigillose. Seeds 1 or 2 (or 3), brown, not mottled, narrowly oblong-reniform, smooth.

Distribution

w North America, nw Mexico.

Discussion

Varieties 2 (2 in the flora).

D. Isely (1981) reported potential hybrids of Acmispon decumbens (variety not specified) with A. argophyllus var. argophyllus and A. glaber var. glaber.

Selected References

None.

Lower Taxa

Acmispon decumbens var. davidsonii, Acmispon decumbens var. decumbens

Key

1	Leaf rachises (3–)5–10(–15) mm; inflorescences (3–)5–12-flowered; flowers 4.5–8(–10) mm; calyces (3.5–)4–7 mm, lobes 0.5–1.5(–3) mm.	Acmispon decumbens var. decumbens
1	Leaf rachises (1–)2–5 mm; inflorescences (1–)3–5(–8)-flowered; flowers 4.5–8(–9) mm; calyces 6–7 mm, lobes 0.5–1.5(–2) mm.	Acmispon decumbens var. davidsonii