两型豆 liang xing dou

Amphicarpaea bracteata (Linnaeus) Fernald subsp. edge­worthii (Bentham) H. Ohashi; A. edgeworthii f. aidzuensis Mat­suda; A. edgeworthii var. japonica Oliver; A. japonica (Oliver) H. Ohashi; A. trisperma (Miquel) Baker; Falcata comosa (Linnaeus) Kuntze var. japonica (Oliver) Makino; F. edge­worthii (Bentham) Kuntze; F. japonica (Oliver) Komarov; Shu­teria trisperma Miquel.

Herbs, annual, 0.3-1.3 m tall. Stems slender. Stipules lan­ceolate or ovate-lanceolate, 3-4 mm, densely pubescent; petiole 2-5.5 cm; stipels extremely small, usually deciduous, narrowly triangular; petiolules usually 2-3 mm; leaflets papery or almost membranous; terminal leaflet rhomboid-ovate or oblate-ovate, 2.5-5.5 × 2-5 cm, both surfaces sparsely yellowish brown vil­lous, base rounded, broadly cuneate or nearly truncate, apex ob­tuse or sometimes with mucro; lateral leaflets usually obliquely ovate or ovate-rhombic, dimorphic. Upper inflorescences axil­lary, shortly racemose; bracts almost membranous, ovate to elliptic, 3-5 mm. Cleistogamous flowers often present. Nor­mal flowers: pedicel 1-2 mm. Calyx tubular, 5-7 mm, 5-lobed; lobes unequal, sparsely pubescent, apex acuminate. Corolla purplish or white; petals subequal; standard obovate, 1-1.7 cm; wings oblong, with long stipes and acute auricles at base; keels similar to wings. Ovary hairy. Cleistogamous flowers under­ground, sessile; style curved. Legumes dimorphic: those of nor­mal flowers oblong or obovate-oblong, 2-3.5 × ca. 0.6 cm, compressed, 2-5-seeded; legumes of cleistogamous flowers elliptic or suborbicular, 1-4-seeded. Seeds reniform-orbicular, 2-4 × 2-3 mm; hilum short. Fl. and fr. Aug-Nov. 2n = 40.

Mountain slopes, roadsides, fields, grasslands; 300-3000 m. An­hui, Fujian, Gansu, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [India, Japan, Korea, Russia, Vietnam].