10. Sophora alopecuroides Linnaeus, Sp. Pl. 1: 373. 1753.
苦豆子 ku dou zi
Herbs or subshrubs, ca. 1 m high, densely branched. Branches white villous or patulous-tomentose. Leaves 15-30 × 4-9 cm; stipules subulate, ca. 5 mm, caducous; petiole 1-2 cm; leaflets 11-27, lanceolate-oblong or elliptic-oblong, 15-40 × 5-14 mm, papery, densely hairy abaxially, pilose adaxially, lateral veins not obvious. Racemes terminal. Flowers many, dense; pedicel 3-5 mm; bracts subulate, caducous. Calyx compressed campanulate; teeth 5, unequally triangular-ovate. Corolla white or creamy white; standard varying in shape, usually oblong-oblanceolate, 15-20 × 3-4 mm, apex rounded or obcordate, narrowing to claw; wings ca. 16 mm, ovate-oblong, 1-auriculate; keel similar to wings, claw slender, ca. 1/2 as long as blade. Stamens 10, slightly fused at base, shortly hairy where fused. Ovary densely white hairy; stigma very small, pilose. Legumes moniliform, straight, 8-13 cm. Seeds many, brown or light brown, ovoid. Fl. May-Jun, fr. Aug-Oct.
Grasslands, deserts. Gansu, Henan, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, Xinjiang, Xizang [Afghanistan, India, Pakistan; C and SW Asia].