Shrubs or small trees, 1.5-5 m tall. Stems brown, terete, with round lenticels; young branches green, angular, with appressed white or brown medifixed symmetrically 2-branched trichomes. Stipules lanceolate-subulate, 3-5 mm, caducous. Leaves ca. 2.4 cm, (7-)11-19(or 21)-foliolate; petiole and rachis with appressed white and brown medifixed trichomes; petioles 2.5-3.5 cm; rachis flattened or adaxially slightly grooved; stipels subulate, as long as petiolules; petiolules 1.5-2.5 mm; leaflet blades opposite, ovate to elliptic, 1.5-6.5(-8) × 1-2.5 cm, membranous, both surfaces with appressed medifixed trichomes or adaxially glabrous, midvein abaxially prominent and adaxially impressed, secondary veins 8-10 on each side of midvein, base broadly cuneate to rounded, apex obtuse, emarginate, or acute and mucronate. Racemes 8-15(-28) cm; peduncle and rachis with sparse appressed medifixed trichomes; peduncle 1.5-2.5 cm; bracts ovate to ovate-lanceolate, 2.5-3.5(-5) mm, abaxially with appressed brown trichomes. Pedicel ca. 1.5 mm. Calyx ca. 2.5 mm, with dense appressed grayish brown medifixed trichomes; teeth triangular, ca. 0.5 mm. Corolla dark purple; standard elliptic, 7-8.5 × 4.5-5.5 mm, glabrous; wings 7-8 mm, margin apically ciliate; keel 7.5-8.5 mm, outside apically hairy, margin ciliate. Stamens 6-7 mm; anthers globose, base with a few trichomes. Ovary glabrous, with 6-9 ovules. Legume cylindric, 2.5-5 cm, with sparse appressed trichomes when young, glabrescent when mature, sutures thickened; endocarp not blotched. Seeds 6-9 per legume, rufous brown, cubic, ca. 1.8 × 1.5 mm. Fl. May-Sep, fr. Aug-Dec. 2n = 16, 32.