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.