Description

Key Characters:

Growth Form: Sprawling annual herbs.

Stems: Stems up to 15 dm long, glabrous, narrowly winged.

Roots:

Leaves: Leaves compound. Alternate. The rachis ending in a well–developed tendril, leaflets 2, opposite or alternate, narrowly oblong–elliptic to linear–lanceolate or narrowly ovate; 2–8 cm long, 0.4–1.5 cm wide, somewhat glaucous. Base semisagittate or semihastate. Margins sometimes toothed. Petiolate. Stipules lanceolate, ovate, or oblong, 1.2–2.5 cm long, persistent.

Flowers: Flowers 1–3 in lax racemes, peduncles (6–)7–9.5 cm long. Flowers papilionaceous; pedicels 0.5–0.7 cm long. Calyx 5-lobed, ca. 9 mm long, the teeth slightly unequal, ca. 3 mm long. Corolla bright purple, standard (20–)30–35 mm long, keel dull purple. Stamens 10; upper stamen connate at least at the middle to the other 9, which are connate into a tube. Ovary superior; style 1, apical, pubescent on upper (adaxial) side ca. ½ its length.

Fruit: Pods linear–oblong; 6–10 cm long; 0.8–1 cm wide; narrowly wing–margined along upper suture; dehiscent. Seeds 6–8; smooth; with a thin aril.

Ploidy: 2n = 14

Habitat: Sparingly naturalized along roadsides and in pastures.

Elevation Range: 915–1,220 m.