Description from Flora of China
Bauhinia sect. Lasiobema Korthals; Lasiobema (Korthals) Miquel; Phanera Loureiro; Piliostigma Hochstetter.
Trees, shrubs, or lianas, hermaphroditic, monoecious, andromonoecious, or androdioecious. Leaves simple, bilobed or entire, rarely 2-foliolate with a shared upper pulvinus; primary veins 3-15, midvein ending with a free, small point; stipules caducous. Inflorescences solitary flowers, or many flowers in racemes, panicles, or corymbs; bracts and bracteoles usually small and caducous. Hypanthium cupular, campanulate, or tubular. Calyx closed or open with 5 short or linear teeth at apex in bud, at anthesis spathaceous, or regularly or irregularly split into 2-5 lobes. Petals 5, subequal to strongly differentiated, subsessile or prominently clawed, white, yellowish orange, pink, or purplish red. Stamens 2, 3, 5, or 10; anthers dorsifixed, longitudinally dehiscent. Staminodes present or not. Ovary 1- to many ovuled, sessile or with stalk; stigma small or prominent, variously shaped. Fruit flat, elliptic, oblong, obovoid, or linear, woody or thinly valved, dehiscent or indehiscent. Seeds few to many; endosperm present or not.
The key is based on flowering material as there are too many species for which the mature legumes are not known. Bauhinia tianlinensis is known only from fruiting material so could not be included in the key. Legumes of China (Zhu et al., 37, 40, 42, 43, 47. 2007) listed a further five species not included in this manuscript: B. clemensiorum Merrill from Guangxi; B. galpinii N. E. Brown cultivated in Hong Kong; B. godefroyi Gagnepain from Yunnan; B. lakhonensis Gagnepain from Guangxi; and B. strychnoidea Prain ex King from Yunnan.
About 300 species: pantropical; 47 species (23 endemic, two introduced) in China.
(Authors: Chen Dezhao (陈德昭 Chen Te-chao), Zhang Dianxiang (张奠湘); Kai Larsen, Supee Saksuwan Larsen)