Description

Key Characters:

Growth Form: Annual herbs.

Stems: Stems erect, up to 20 dm long, ridged, glabrous or nearly so, taproot with slender branches, nodules often present.

Roots:

Leaves: Leaves simple. Alternate. Blades elliptic, rhombic–obovate, or oblanceolate, 5.5–14 cm long, 2.8–7.4 cm wide. Apex rounded and often mucronate. Base cuneate. Upper surfaces glabrous and slightly punctate; lower surfaces sparsely to densely appressed pubescent. Margins entire. Veins 6–11 on each side of midvein. Petioles 4–7 mm long. Stipules triangular, up to 10 mm long.

Flowers: Flowers in racemes, flowers 15–27 mm long, 15–40 in terminal or axillary, somewhat lax inflorescences, rachis 13.5–42 cm long (incl. peduncle), bracts ovate, 8–15 mm long, spreading, usually persistent. Flowers papilionaceous; bracteoles at or below mid–pedicel, ovate to triangular. Calyx glabrous, the tube 5.5–7.5 mm long, the lobes 5.5–10 mm long, lateral lobes distinct at apex. Calyx slightly bilabiate, the lobes shorter than to longer than the tube. Petals yellow, standard 12–16 mm long, 14–18 mm wide, wings broadly oblong, 9–12 mm long, 7.5–11 mm wide, keel petals short, beak twisted and ciliate, margins ciliate. Stamens 10, connate into a tube, the tube split at least at base on the upper side; anthers dimorphic, alternately long (and basifixed) and short (and versatile). Elongated anthers 2.5–3.1 mm long, short ones 0.7–1 mm long. Ovary superior.

Fruit: Pods brown or dark brown at maturity;3.2–4 cm long; nonstipitate; glabrous. Seeds ca. 22 per pod; dark brown up to 4.5 mm long; smooth.

Ploidy: 2n = 16

Habitat: Disturbed areas.

Elevation Range: 50–120 m.