Authors: K. & S.S. Larsen
Morphological description (see also description of Genus Bauhinia ; Subgenus Phanera and Section Phanera)
Large tendrilled climber; young branches silky reddish-brown, later glabrous.
Leaves: stipules lanceolate, reddish woolly outside, inside subglabrous, c. 4 mm long, early caducous; petioles 3-5 cm, rusty tomentose; lamina ovate to orbicular, 4-10 by 4-12 cm; 11-13-nerved; bifid 1/4-1/3 with broad sinus; tip of lobes rounded to acute or acuminate; base deeply cordate; upper surface sparsely yellowish-brown to coppery pubescent, particularly along the nerves, lower reddish-brown puberulous, mainly on the nerves.
Inflorescence terminal and lateral, compound or simple, dense corymbs; pedicels up to 2 cm, greyish pubescent; bracts narrow lanceolate acuminate, 4-6 mm, outside appressed hirsute; bracteoles subulate, 2-4 mm, inserted 1-3 mm below the hypanthium.
Flowers: Buds ovoid, with pointed apex, 4-5 mm, greyish pubescent. Hypanthium short, c. 2 mm. Calyx splitting into 2-3, later often 5 free sepals, c. 7 mm long, reflexed. Petals yellowish-white, narrowly oblong, subequal, 7-10 mm long, margin crenate-undulate, gradually narrowing into the indistinct, greenish claw, outside densely appressed hirsute, inside glabrous. Stamens 3 fertile; filaments 5-6 mm, glabrous; anthers red, c. 2 mm; staminodes 2, minute, subulate. Ovary appressed hirsute, subsessile, c. 3 mm; style hirsute; stigma peltate.
Pods broadly oblong, c. 17 by 5.5 cm; young pods with light brown indumentum; mature pods almost glabrous (see Note).
Seeds 3-4, flat, oval, c. 2 cm diameter.
Distribution
Malesia: Borneo (Sabah, Sarawak, W and E Kalimantan).
Habitat
Lowland evergreen forests, often along rivers.
Vernacular names
Kulalong (Dusan-Kinabatangan), Kubalid (Malay).
Notes
1. This species is closely related to Bauhinia fulva ; Larsen & Larsen (1996: 468) have kept it at specific level as they found it fairly well distinguished by the small, more gracile floral structures, the hairy style and several quantitative characters. Only one specimen has a mature pod, a very old one; if the pod really is glabrous this is another good character distinguishing it from B. fulva.
2. In this species there is a wide variation in the indumentum of the leaves and inflorescences from densely hairy to almost glabrous. Also the shape of the leaves varies considerably. One specimen, Argent & Coppins 1148 (AAU, E) from Mount Mulu has leaves glabrous or nearly so and tip of lobes caudate; the inflorescence is almost glabrous, the flowers somewhat larger, and the style subglabrous. When more material from Mount Mulu is available, it may be established as a separate variety.