Description

Key Characters:

Growth Form: Prostrate annual herbs.

Stems: Stems up to 5 (–10) dm long, spreading long–villous, the hairs white or brown.

Roots:

Leaves: Leaves compound. Alternate. Leaflets ovate to elliptic or obovate, 5–22 mm long, 1–10 mm wide. Leaves appearing trifoliate, but actually pinnately 5–foliate with a basally placed pair of leaflets. Surfaces long–villous. Leaflet margins entire. Petiolate. Stipules present.

Flowers: Flowers (1)2–4 in heads, peduncles usually more than 10 mm long. Flowers papilionaceous. Calyx teeth 1.5–3 times as long as the tube, long–villous, 5-toothed. Corolla yellow with red veins, 5–13 mm long, keel obtusely angled on lower edge, long–beaked, standard obovate, wing petals oblong, auriculate, keel petals as long as wings, curved. Stamens 10; upper stamen distinct, the other 9 connate into a tube, alternately with longer filaments that are widened at apex. Ovary superior; ovules numerous; style 1, apical, bent abruptly upward at base.

Fruit: Pods straight; dehiscent with twisted valves; less than 3 times as long as calyx; (4–)6–12(–16) mm long; 1.5–2 mm wide; the valves contorting after dehiscence. Seeds 8–13; small.

Ploidy: 2n = 12; 24

Habitat: Pastures and along roadsides and trails.

Elevation Range: 640–1,160 m.