Herbs, perennial, mat-forming, silvery or gray, 1–3 dm, not fleshy, sericeous to canescent; from woody caudices. Stems 1–20+, procumbent or decumbent to diffusely ascending, branched, herbaceous, slender, leafy. Leaves palmate or irregularly subpinnate; stipules glandlike; subsessile to short-petiolate; rachis 1–4 mm, ± flattened; leaflets 3–5, blades obovate to oblanceolate, apex usually obtuse, sometimes acute, surfaces sericeous to canescent. Peduncles ascending or spreading, (2–)10–20 mm, shorter to longer than leaves; bract absent (reduced to stipules) or unifoliolate, distal. Inflorescences 1–3(–5)-flowered. Flowers 5–12 mm; calyx 4–7 mm, tube villous, lobes subulate; corolla yellow, turning orange-red, claws ± equaling calyx tube, banner ascending to 45°, wings unequal, longer than keel; style slightly curved or straight, glabrous or finely puberulent. Legumes persistent, exserted, divergent, brown, straight or curved at tip, turgid, slightly constricted, imperfectly septate, linear-oblong to oblong, (10–)18–25 × 1.5–2 mm, leathery, apex short-beaked, dehiscent, smooth, margins smooth, strigillose to glabrate. Seeds 2–5+, olive brown, mottled, roundish-oblong to angled, smooth, 2-veined.

Distribution

California, nw Mexico.

Discussion

Varieties 3 (3 in the flora).

Acmispon argyraeus (variety not specified) is reported to hybridize with A. rigidus (A. M. Ottley 1944).

Selected References

None.

Lower Taxa

Acmispon argyraeus var. argyraeus, Acmispon argyraeus var. multicaulis, Acmispon argyraeus var. notitius

Key

1	Banner panduriform; pistils arched more than 90°, ovary-style junction defined by a line; leaflet blades oblanceolate to obovate, usually folded; legumes curved at tip.	Acmispon argyraeus var. multicaulis
1	Banner not panduriform; pistils arched less than 90°, ovary-style junction with a jog (style base broader than apex of ovary) or confluent; leaflet blades obovate, not folded; legumes usually straight.	> 2
2	Herbs usually prostrate; stems branched, silvery-canescent; ovary-style junction with a jog; flowers 5–10 mm.	Acmispon argyraeus var. argyraeus
2	Herbs low-spreading or low-ascending; stems diffusely branched, green or canescent; ovary-style junction confluent; flowers (8–)10–12 mm.	Acmispon argyraeus var. notitius