Description from Flora of China
Indigofera amblyantha var. purdomii Rehder.
Shrubs, erect, 0.8-2(-3) m tall. Stems brown to pale brown, terete; young branches 4-sided, with dense appressed white medifixed symmetrically 2-branched trichomes, glabrescent. Stipules triangular-lanceolate, ca. 1.5 mm. Leaves to 18 cm, 5-9(-13)-foliolate; petiole and rachis with appressed medifixed trichomes; petiole (1.5-)2-5 cm; stipels minute; petiolules ca. 1.5 mm, hairy; leaflet blades opposite or rarely alternate, obovate-oblong, oblong-elliptic, elliptic, or orbicular, 1-4(-5) × 0.8-2 cm, abaxially pale and with dense appressed medifixed trichomes, adaxially green and with sparse appressed medifixed trichomes, midvein abaxially prominent and adaxially impressed, secondary veins 4-6 on each side of midvein, base cuneate to broadly cuneate, apex rounded-obtuse and mucronate. Racemes 11-15 cm, subspicate, sessile or peduncle to 5 mm; bracts linear, ca. 2 mm, caducous. Pedicel 1-2(-2.5) mm. Calyx 2-3.5 mm, with appressed white medifixed trichomes; tube 1-1.5 mm; teeth 1.5-2 mm. Corolla pink; standard obovate, 6-6.5 mm, somewhat hooded at apex, outside hairy; wings ca. 7 mm; keel shorter than wings. Stamens 5-6 mm; anthers globose, apex mucronate. Ovary linear, hairy, with 17 or 18 ovules. Legume brown, cylindric, straight, 3.5-6 cm, with short appressed medifixed trichomes; endocarp not blotched. Seeds brown, ellipsoid, ca. 2.5 mm. Fl. May-Jul, fr. Sep-Nov. 2n = 48*.
● Grasslands near streams, trailsides, scrub at forest margins; 600-1600 m. Anhui, Chongqing, Gansu, Guizhou, Hebei, Henan, Hubei, NW Hunan, Jiangsu, NW Jiangxi, Shaanxi, Shanxi, Sichuan, Zhejiang.