Description from Flora of China
Ervum Linnaeus; Faba Miller; Vicioides Moench.
Herbs annual or perennial. Stem usually branched, erect, trailing, or climbing by means of tendrils, usually slender, wingless. Leaves paripinnate with rachis terminating in a tendril, bristle, or mucro, rarely imparipinnate with rachis terminating in a leaflet (Vicia subvillosa); stipules entire or toothed at margin; leaflets 1-13-paired, margin entire. Inflorescence a raceme, or flowers in axillary fascicles or solitary; bracts usually absent or caducous. Calyx ± campanulate, equally or unequally toothed, often hairy; teeth not leaflike, at least 2 teeth less than 2 × as long as tube. Corolla various shades of blue, purple, red, yellow, or white; standard with a proximal claw and distal limb, apex retuse. Stamens diadelphous; staminal tube oblique at apex; filaments filiform. Ovary stalked or subsessile; ovules 2-8; style terete, hairy all round distal part, hairy on lower side, or glabrous. Legume usually compressed, dehiscent along sutures. Seeds 2-8, globose, oblate, or oblong; hilum often elongate.
About 160 species: N temperate zone, extending to tropical E Africa, Pacific islands (Hawaii), and South America; 40 species (13 endemic, three introduced) in China.
(Authors: Bao Bojian (包伯坚); Nicholas J. Turland)