Herbs, annual, solitary or cespitose, green, 0.5–6(–12) dm, not fleshy, glabrate to ± pilose; taprooted. Stems 1–10+, erect to procumbent, branched proximally, herbaceous, leafy. Leaves pinnate; stipules glandlike; subsessile to short-petiolate; rachis 0.5–3(–4) mm, not flattened; leaflets (1–)3(–5), blades obovate, ovate, or elliptic to lanceolate, margins denticulate or entire, apex acute, surfaces sparsely appressed-hairy. Peduncles in distal axils, ascending, 3–25 mm, longer than leaves; bract unifoliolate, distal. Inflorescences 1(or 2)-flowered. Flowers (4–)5–9 mm; calyx (2.5–)3–6.5 mm, tube pilose, lobes linear-lanceolate, accrescent; corolla whitish or cream, turning pink or salmon, banner rose-striate, keel tip yellow, claws shorter than calyx tube, banner implicate-ascending to erect, wings ± equaling keel; style abruptly angled upward 45°, glabrous. Legumes persistent, exserted, spreading or pendent, brown, straight or ± curved, compressed, slightly constricted, not septate, linear-oblong to narrowly oblong, (15–)20–30(–40) × (1.5–)2–2.5 mm, thinly leathery, apex abruptly downward angled and curved, dehiscent, smooth, margins smooth, thickened, glabrous. Seeds (3–)5–8, olive to light brown, often black-mottled, oblong, smooth.

Distribution

North America, nw Mexico.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Lower Taxa

Acmispon americanus var. americanus, Acmispon americanus var. helleri

Key

1	Herbs usually conspicuously pilose, sometimes glabrate; leaflet blades: length 3–3.5 times width.	Acmispon americanus var. americanus
1	Herbs glabrate; leaflet blades: length 4–5 times width.	Acmispon americanus var. helleri