Description from Flora of China
Herbs, twining. Leaves pinnately 3-foliolate; stipules narrow. Inflorescence axillary, racemelike, sometimes 1- or 2-branched; flowers solitary or fascicled at nodes. Bracts membranous, enlarging after anthesis, leaflike, boat-shaped. Calyx membranous, 5-lobed, upper 2 lobes connate. Corolla white; petals clawed; standard nearly orbicular, with paired calluses above auricles; wings oblong, auriculate; keel incurved, shortly auriculate. Vexillary stamen free; anthers uniform. Ovary nearly sessile, with annular disk around base; ovule 1; style slightly thickened above. Legume broadly elliptic, indehiscent, compressed, reticulate veined. Seed 1, reniform or orbicular.
Phylacium was originally placed within the Desmodieae, largely because of the indehiscent fruit; but the twining habit is anomalous within the tribe, and the genus is now regarded as a member of the Phaseoleae.
Three species: China, India, Laos, Malaysia, Myanmar, Philippines, Thailand; one species in China.
(Authors: Huang Puhua (黄普华 Huang Pu-hwa); Hiroyoshi Ohashi)