Description from Flora of China
Baptisia nepalensis Hooker, Exot. Fl. 2: 131. 1824; Piptanthus bicolor Craib; P. bombycinus C. Marquand; P. concolor Harrow ex Craib; P. concolor subsp. harrowii Stapf; P. concolor subsp. yunnanensis Stapf; P. forrestii Craib; P. laburnifolius (D. Don) Stapf; P. laburnifolius f. nepalensis Stapf; P. laburnifolius f. sikkimensis Stapf; P. leiocarpus Stapf; P. leiocarpus var. sericopetalus P. C. Li; P. nepalensis f. leiocarpus (Stapf) S. Q. Wei; P. nepalensis var. leiocarpus (Stapf) X. Y. Zhu; P. nepalensis f. sericopetalus (P. C. Li) S. Q. Wei; P. nepalensis var. sericopetalus (P. C. Li) X. Y. Zhu; Thermopsis laburnifolia D. Don.
Shrubs, 1.5-3 m tall. Stems terete, ridged, white woolly to appressed pubescent, glabrescent. Stipules lanceolate to ovate, 7-14 mm; petiole 1-3 cm, with a wide groove adaxially; leaflets elliptic, oblong-elliptic, or linear-ovate, 4-14 × 1.5-4 cm, flat on both surfaces, papery, dark green, yellow silky and white appressed pubescent abaxially, gradually glabrescent, becoming glaucous, glabrous or sparsely hairy along midrib adaxially, lateral veins 6-8 pairs, base cuneate, margins sometimes ciliate, apex acute or acuminate. Racemes terminal, 5-8 cm, with flowers in 2-7 whorls, axis densely white woolly, elongating at anthesis; bracts broadly ovate to obovate, 7-12 mm, acute; pedicels 1.5-2.5 cm. Calyx campanulate, 1-1.6 cm, white woolly. Corolla bright yellow, 1.8-2.6 cm; standard orbicular to broadly cordate, with 4-6 mm claw; wings shorter; keel equal to or slightly longer than standard, to 2.2 cm. Ovary stipitate, densely sericeous to almost glabrous, 4-10-ovuled. Legume broadly linear, flat, 7-15 × 0.9-1.5 cm, stipitate, apex sharply pointed; valves membranous, reticulate, glabrous to very sparsely pubescent. Seed brown, reniform, 4-5 × 3-3.5 mm, compressed. Fl. Apr-Jul, fr. Jun-Sep.
This is a very variable species, and several taxa have been distinguished on the basis of variation in the indumentum of the ovary, legume, and leaves. Turner (Brittonia 32: 281-285. 1980) revised the genus and concluded that variation in these characters was continuous and that only two taxa should be recognized, and we agree. Even Piptanthus tomentosus could be considered to be a very hairy higher-elevation ecotype, but it is here retained as distinct.
Coniferous forests, woodland margins, thickets, meadows; 1600-4000 m. Gansu, Shaanxi, Sichuan, Xizang, Yunnan [Bhutan, India, Kashmir, Nepal].