Author: L.
Morphological description (see also description of Genus Bauhinia and Subgenus Bauhinia )
Shrub or small tree up to 10 m. Young branches glabrescent (purpurea Bauhinia habit 386301 ).
Leaves: stipules minute, 1-2 mm long; petiole 2-3 cm; lamina suborbicular up to 12 cm diameter, 9-13-nerved; bifid 1/3-1/2 with narrow to broad sinus; tip of lobes rounded to acute, base rounded to cordate; upper surface glabrous, lower sparsely hairy (purpurea Bauh lf/fl/infl FT1).
Inflorescence: (purpurea Bauh fl 386336) lateral and terminal racemes, 6-l0-flowered; pedicels thick, 1-1.5 cm; bracts ovate acute, 1-2 mm long; bracteoles similar, inserted at about the middle of the pedicel.
Flowers: ( purpurea Bauh lf/fl/infl FT1 )Buds clavate, velvety, greyish-green, 4-5 angled mainly towards the ± twisted apex, 3-4 cm long. Hypanthium turbinate, 7-12 mm long. Calyx splitting spathaceous. Petals narrowly lanceolate, the posterior oblanceolate, 3-5 cm long, claw 5-10 mm, pink to dark purple. Stamens 3 fertile; filaments shortly connate at base, 3-4 cm long; anthers 5-7 mm long, opening by a longitudinal slit; staminodes 5-6, filiform, 6-10 mm long. Ovary velvety, 1 cm long, stipitate, stipe 1 cm; style short; stigma oblique, flat.
Pods dehiscent, linear, 20-25 by 1.5-2.5 cm, glabrous, irregularly veined (purpurea Bauhinia habit 386301 ).
Seeds c. 10; flat, orbicular, c. 15 mm diameter.
Distribution
Native of tropical Asia, probably only in the continental monsoon area northwest to Nepal. Cultivated throughout S and SE Asia; it occurs occasionally as an escape from cultivation as e. g. in Java near Songgoriti, altitude 1000 m.
Vernacular names
Kupu kupu (Madura); Tapak, Kuda (Malaya); Suwoto (Java); Lupit (Sabah); Alibangbang (Philippines, Tag.); Snijbonenboom (Dutch); Orchid tree (Engl.).
Notes
1. There is a certain variation in flower colour from deep purple to pale pink, in the opinion of Larsen & Larsen (1996) without taxonomic significance.
2. The sterile hybrid Bauhinia purpurea x variegata [B. blakeana Dunn, J. Bot. Lond. 4 (1908) 325; de Wit, Reinwardtia 3 (1956) 397] is also widely cultivated and according to the experience of Larsen & Larsen (1996) more common than B. purpurea as wayside and park tree (blackeana ? Bauh fl 431673 ; blakeana Bauhinia fl 256026 ;blakeana Bauhinia fl/lf 256027 ). The pollen is very irregular and probably most of it not viable; pods are usually not produced. It is rather intermediate between the parents in floral morphology but has 5 stamens as Bauhinia variegata.