Bauhinia kostermansii

Authors: K. & S.S. Larsen

Morphological description (see also description of Genus Bauhinia ; Subgenus Phanera and Section Phanera )
Tendrilled liana , young branches terete, ferrugineous pubescent, later glabrous.

Leaves: stipules obovate with truncate, dentate apex, 8-10 by 3-6 mm, sparsely hairy on both sides, tardily caducous; petiole c. 5 mm, pubescent; lamina coriaceous, ovate, 3.5-5.1 by 3.5-3.8 cm; 11-13-nerved, nerves prominent on the lower side; bifid 1/3 or less (deeper on sterile shoots); tip of lobes obtuse, base truncate to shallowly cordate; upper surface glabrous, lower pubescent (kostermansii Bauh lv+fl FM9).

Inflorescences few-flowered, terminal and lateral racemes, sometimes joined in larger panicles; axis very short, 1-2 cm, ferrugineous-tomentose as all external parts of the inflorescence; pedicels 2-6 mm; bracts lanceolate, acuminate, c. 5 mm, silky hairy; bracteoles smaller, narrowly lanceolate, subulate, inserted about the middle of the pedicel. Hypanthium 3.5-4 cm long, gradually tapering into the pedicel.

Flowers: Buds clavate, apiculate with truncate base, calyx splitting into 5 strap-shaped, early caducous sepals. Petals white turning green, outside densely silky hairy, inside glabrous, unequal; lamina lanceolate, 15-20 mm long, 9-15 mm broad, upper one broader and slightly shorter, distinctly clawed, claw 4-7 mm. Stamens 3 fertile, early caducous; filaments 12-18 mm; anthers 2-3 mm, opening by a longitudinal slit; staminodes 2, c. 5 mm. Ovary ferrugineous tomentose, shortly stipitate, c. 15 mm including the style; style tomentose, short, glabrous just below the capitate stigma.

Pods glabrous, rugulose, obovate-oblong, 11.5-12.5 by 4.5-5 cm, with a strong beak (kostermansii Bauh pod FM9).

Seeds 2-3 (ripe seeds not seen).

Malesia: Borneo (Sabah and E Kalimantan along the Berau River).

This species is related to Bauhinia lingua which, however, does not occur on Borneo. The pedicels of the present species are much shorter and the hypanthium is longer. The small leaves are very distinctive. Kostermans writes that the white flowers turn green; this is unusual; in other white flowered species of this group they become cream-coloured with age.