Description

Key Characters:

Growth Form: Annual herbs.

Stems: Stems prostrate, not rooting at the nodes, 2–3 dm long, unbranched or few–branched, villous.

Roots:

Leaves: Leaves compound. Alternate. Leaflets broadly obovate or obcordate, 8–20 mm long and wide. Surfaces villous, lower surface more densely so. Margins subentire to minutely denticulate. Lateral veins ending at margins. Petiolate. Stipules elliptic to obovate, adnate to petioles up to 1/2 their length.

Flowers: Flowers in heads, axillary, loose, obovoid, usually few–flowered, ca. 10 mm long, peduncles slender, 15–40 mm long, flowers dimorphic within each head, the outer ones fertile, bearing a corolla, the inner ones sterile, only consisting of a modified calyx with 5 patent, stiff teeth ca.3.5 mm long and a solid linear tube ca. 3 mm long, elongating beyond the pods and recurving in fruit, thereby encaging the pods and pulling the fruiting head into the plant litter, bracts absent, bracteoles absent. Flowers papilionaceous. Calyx of fertile flowers with tube 3–3.2 mm long, the throat open, glabrous, the teeth 3.5–3.7 mm long. Corolla of fertile flowers white with pink stripes, 8–14 mm long. Stamens 10; upper stamen distinct, the other 9 connate into a tube. Ovary superior.

Fruit: Pods obovoid; ripening underground; exserted from the accrescent calyx tube. Seeds 1 per fruit; black; lenticular.

Ploidy: 2n = 12; 16

Habitat: Mid-elevation pastures.

Elevation Range: