Herbs perennial. Stems erect, trailing, or climbing, slender to stout, to 20 dm. Leaves 2–8 cm; tendrils simple or branched; stipules much smaller than leaf­lets, semisagittate, without nec­tariferous patch; leaflets 8–18, blades ovate or elliptic to linear, 3–44 × 1–19 mm, apex obtuse to truncate-emarginate, or apiculate, surfaces glabrous or finely pubescent. Inflorescences 3–9-flowered, 2–8 cm, shorter than or equal to subtending leaf rachis. Flowers 12–25 mm; calyx base symmetric, lobes subequal, shorter than tube; corolla usually bluish purple, rarely white, banner oblong, blade equal to claw, glabrous; style compressed abaxially, pubescent apically, tufted abaxially. Legumes tawny to brown, oblong, 25–39 × 5–9 mm, oblique-tipped, glabrous or pubescent; stipe to 4–5 mm. Seeds: number not known, olive-brown to deep violet-brown, subglobose, 3–4 mm diam.; hilum encircling 1/4–1/3 circumference of seed.

Distribution

North America, n Mexico, e Asia.

Discussion

Varieties 3 (2 in the flora).

Vicia americana consists of a polymorphic assem­blage of populations among which leaflet size, shape, and vestiture is variable. Intergradation is widespread. C. R. Gunn (1968) described two relatively distinct entities which may represent the extremes of a continuum of variation in some regions. Variety sinensis C. R. Gunn occurs in eastern Asia.

Selected References

None.

Lower Taxa

Vicia americana var. americana, Vicia americana var. minor

Key

1	Stems usually 4–20 dm, trailing or climbing; leaves with branched tendrils; inflorescences (3–)4–9-flowered.	Vicia americana var. americana
1	Stems usually to 4 dm, erect; leaves often with simple tendrils; inflorescences 3–4(–5)-flowered.	Vicia americana var. minor