Author: Roxb.
Morphological description (see also description of Genus Bauhinia ; Subgenus Phanera and Section Phanera)
Large, tendrilled (ferruginea Bauh lv/tendrils FM8) climber ; branches glabrescent.
Leaves: stipules orbicular to ovate-orbicular or reniform, foliaceous, glabrous to sparsely hairy mainly inside, 10--28 mm; petiole 2--4 cm; greyish pubescent when young, soon glabrous; lamina ovate-orbicular, 7--10 by 7--8 cm, 9--11-nerved; bifid 1/3; tip of lobes obtuse, base cordate; upper surface glabrous, lower minutely pubescent when young, soon glabrous; rarely pubescent on the nerves.
Inflorescence (ferruginea Bauh infl 386329 , ferruginea Bauh fl FM8bcd ) terminal, corymbose to pyramidal racemes with a greyish to ferrugineous tomentose axis; pedicels puberulous to almost glabrous, 1--2 cm long; bracts varying, usually ovate or lanceolate, 7--15 mm long; bracteoles narrower, lanceolate, inserted in the lower half of the pedicel. Buds ellipsoid-clavate, greyish to ferrugineous pubescent to almost glabrous, c. 15 mm. Hypanthium 10--15 mm, striate with dilated base. Calyx early splitting into 5 reflexed sepals. Petals creamy-white turning yellowish, rarely pinkish-red; densely woolly tomentose on the outer side, glabrous inside, 3--4.5 cm long, lanceolate, claw short, indistinct; during anthesis margins of the petals becoming recurved, later the whole lamina recurved. Stamens 3 fertile, filaments pink, glabrous, 5--6 cm; anthers oblong, red, c. 5 mm, opening by a longitudinal slit; staminodes 2--3 (or more?), 12--20 mm, sometimes with minute anthers. Whole gynoecium densely ferrugineous tomentose, rapidly lengthening during anthesis; stipe 1-2 cm; ovary c. 1 cm; style 1-2.5 cm; stigma large, peltate.
Pollen : ferruginea Bauh pol 386330
Pods dehiscent, woody, 15 by 4-6 cm, glabrous.
Seeds few, 2-2.5 cm diameter.
Distribution
From S Thailand throughout the Malay Peninsula and with a single record from eastern Sumatra.
Habitat
Most collections are from the lowlands, but it is found up to 800 m altitude, in forest margins, on sandy loam and on sandy soil in the peat swamp forests in S Thailand.
Vernacular name
Lapang (for var. ferruginea).
Notes
1. Bauhinia ferruginea is a well defined species easily recognized by the unique character of the petals, first erect, then with recurved margins and finally the whole petal entirely curving downwards. Flower colours are by various collectors described from white or creamy turning yellowish, to pinkish. The petals are usually (always?) white to yellowish with age, the stamens pink to red and the anthers red.
2. Larsen & Larsen (1996) have found that the two taxa 'ferruginea ' and 'griffithiana ' are difficult to distinguish; they are mainly based on the presence or absence of stipules in herbarium material and on the colour of the indumentum. How much these characters are due to geographical and ecological conditions have still to be studied in nature. Larsen & Larsen (1996) have studied populations in southern Thailand of var. ferruginea and found that while the flowering branches shed the stipules, these were kept longer on young sterile shoots. Some collections from Penang (e. g. Potts s. n. in G) have smaller, ovate stipules on the tendrils, but apart from this they have not observed 'small falcate stipules' as mentioned by de Wit (1956). Larsen & Larsen (1996) did choose to maintain the two taxa as varieties as there are several examples that transition forms occur, on the other hand, with their present knowledge, it seems that there is difference in the distribution between var. ferruginea and var. griffithiana.
KEY TO THE VARIETIES
1a. Stipules on flowering shoots early caducous; indumentum of inflorescence axis and buds usually ferrugineous; bracts pubescent, lanceolate, 5-10 mm; bracteoles smaller a. Bauhinia ferruginea ferruginea
1b. Stipules on flowering shoots tardily caducous; indumentum of inflorescence axis and buds usually greyish to light brown; bracts sparsely pubescent, ovate-carinate, 10-15 mm b. Bauhinia ferruginea griffithiana
a. Bauhinia ferruginea Roxb. var. ferruginea (Bauhinia ferruginea ferruginea )
This seems to be the rarer variety, known only from S Thailand, Penang I., Perak, Trengganu, and Selangor, i. e. the northern part of the distribution area only.
b. Bauhinia ferruginea Roxb. var. griffithiana (Benth.) Baker (Bauhinia ferruginea griffithiana )
This is found all over the Malay Peninsula, but not in S Thailand, and moreover in a single locality in E Sumatra.