纤柄红豆 xian bing hong dou

Trees, 6-30 m, to 50 cm d.b.h. Branchlets brownish, gla­brous or inconspicuously pilose. Leaves imparipinnate, 25-49 cm; petiole 6.5-7.5 cm; rachis 12-17 cm, prolonged 0.3-1.7 cm below terminal leaflet; leaflets 7-9; petiolule 5-8 mm, thick, rough; blades pale green abaxially, green or olive-green adaxi­ally, narrowly oblong or broadly oblong-lanceolate, 12-24 × 2.5-6.2 cm, papery, glabrous or very sparsely white pubescent, base acute to cuneate, apex acuminate to caudate; lateral veins 8-10 pairs, conspicuously raised, arcuate, anastomosing. Pani­cles terminal, to 26 cm, branches few at base, up to ca. 18 cm, flowers sparse; pedicel 5-6 mm, peduncle and pedicel glabrous or sparsely grayish pubescent; bractlets acicular, caducous or absent, glabrous or grayish hairy. Calyx ca. 1.2 cm; teeth ob­long, ca. 7 mm, both surfaces grayish pubescent. Corolla russet-red; standard suborbicular, ca. 10 × 12 mm, apex retuse, claw ca. 1 mm, thickened at base; wings obovate-elliptic, ca. 1 × 0.4 cm, claw ca. 2 mm; keel elliptic, ca. 9 × 5 mm, laterally 1-auriculate, claw ca. 3 mm. Stamens unequal, 7-13 mm. Ovary sparsely yellow pubescent, becoming glabrescent. Legumes elliptic or oblong-elliptic, 3.5-4 × ca. 2.5 × 2 cm, stipe ca. 5 mm; valves brownish or black, ca. 1 mm thick, leathery, gla­brous, rugose, internal septum absent. Seeds 1-3, elliptic or ovate, 2-2.3 × 1.7-2.3 × ca. 1.8 cm; testa brownish, fragile, easy to separate from cotyledon; hilum small, inconspicuous. Fl. Jul, fr. Sep-Oct.

● Valleys and streamsides in dense or open forests; 1000-1600 m. SE Yunnan.