1. Zenia insignis Chun, Sunyatsenia. 6: 196. 1946.
任豆 ren dou
Trees, 15-20 m tall. Trunk to 100 cm d.b.h. Branchlets blackish brown, with scattered, yellowish white, small lenticels. Bark rough, exfoliating in strips. Buds elliptic-fusiform, with few scales, yellowish pubescent at first, glabrescent. Leaves 25-40 cm; petiole short, 3-5 cm; rachis and petiole ± yellowish puberulent; petiolules 2-3 mm; leaflets oblong-lanceolate, 6-9 × 2-3 cm, thinly leathery, abaxially grayish white strigose, adaxially glabrous, base rounded, margin entire, apex shortly acuminate or acute. Panicles terminal; peduncles and pedicels yellow or brown strigose. Flowers red, ca. 1.4 cm; bracts caducous, narrowly ovate, small. Sepals oblong, slightly unequal in size, 10-12 × 5-6 mm, thickly membranous, outside strigose, inside glabrous, apex rounded. Petals slightly larger than sepals, ca. 1.2 cm, uppermost one obovate, ca. 8 mm wide, others elliptic-oblong or obovate-oblong, 5-6 mm wide. Filaments ca. 3 mm, puberulent; anthers ca. 6 × 1 mm. Ovary 7-9-ovuled, margin adpressed pilose; stalk ca. 4 mm. Legume reddish brown, oblong or elliptic-oblong, usually ca. 19 cm, sometimes to 15 × 2.5-3.5 cm; wing 5-6 mm wide. Seeds brownish black, shiny, 4-9 × ca. 7 mm, smooth; funicle filiform, ca. 4 mm. Fl. May, fr. Jun-Aug. 2n = 28*.
Dense or sparse forests, mountain slopes; 200-1000 m. Guangdong, Guangxi, ?Yunnan [Vietnam].