Bauhinia bidentata

Author: Jack

Morphological description (see also description of Genus Bauhinia ; Subgenus Phanera and Section Palmatifolia )
Large, tendrilled climber; young branches tomentose, later glabrous.

Leaves entire or emarginate (bidentata Bauh div var Reinwf20 ); stipules broadly falcate to auriculate, c. 5 mm long, early caducous; petioles slender, 1-5 mm; lamina with more or less cordate to truncate base; apex acute, emarginate or very shallowly bifid (1/4 at most); nerves 4-7; much varying in size, up to 14.5 by 12 cm; upper surface usually glabrous or nearly so; lower hairy in varying degree.

Inflorescence corymbose, often elongating during anthesis, up to 10 cm, axis and other floral parts including the buds more or less hairy; pedicels slender; bracts ovate-triangular to linear-lanceolate, 2-10 mm, early caducous; bracteoles smaller, 1-6 mm (bidentata Bauh overv 386322 ).

Flowers: Buds ovoid apiculate. Hypanthium tubular, striate, 5-25 mm (at anthesis). Calyx splitting into 3(-4) reflexed lobes. Petals yellow turning red, unequal, obovate, shortly but distinctly clawed, 15-22 mm long. Stamens 3 fertile; filaments glabrous or hairy, 2-9 mm, usually enlarged at base; anthers 2-3 mm, opening by a central pore in each theca; staminodes 2-7, usually much smaller than the stamens, sometimes with diminutive anthers. Ovary 3-5 mm, on a c. 3 mm long stipe, hairy all over or along the suture only; style c. 3 mm; stigma capitate to small peltate.

Pollen: bidentata Bauh pol 386323.

Pods oblong, up to 10 cm long, glabrous.

Seeds up to 5, flat, c. 1 cm across.

Malesia: Sumatra, Malay Peninsula.

A variable species found from the lowland rain forest to the mountain forests at 1500 m altitude, along streams and forest margins.

1. Bauhinia scortechinii Prain is only known from the type specimen from Perak, G. Haram. A specimen in K, consisting of two short flowering branches with closed buds, has been studied. The specimen, together with Prain's description, clearly indicates that it belongs to Bauhinia bidentata . It has, however, not been possible to place it with certainly under any of the varieties as mentioned below.
2. The type of Phanera bicornuta Miquel (U) consists of two sterile branches, some loose leaves, a loose pod and one seed. This specimen was treated by de Wit under Phanera bidentata as subsp. bicornuta. Nothing in the material suggests that it belongs here; most certainly it belongs to Bauhinia integrifolia , even Miquel writes in the protologue that it is close to Phanera polyantha (= Bauhinia integrifolia) .
However the drawings of Bauhinia bidentata var. bicornuta in both Flora of Thailand 4.1, f. 5 (bicornuta Bauhinia FT5 ) and in De Wit (1956) p. 496, f. 20 (bidentata Bauh div var Reinwf20 ) seems to belong to Bauhinia bidentata , because of the pore like openings of the anthers, while in Bauhinia integrifolia the anther opening is slit-like.

1a.   Filaments of fertile stamens hairy    2
1b.   Filaments of fertile stamens glabrous, rarely glabrescent    6
2a.   Hypanthium 10-20 mm; bracts 2-3 mm, bracteoles 1-2 mm; flower buds glabrous to densely hairy    3
2b.   Hypanthium 5-10 mm, flower buds densely hairy    5
3a.   Flower buds glabrous or glabrescent; ovary hairy along sutures, stipe hairy   
b. Bauhinia bidentata breviflora
3b.   Flower buds hairy; ovary hairy all over or laterally glabrous, stipe hairy    4
4a.   Hypanthium slender, 10-20 mm, buds rusty pubescent, ovary hairy all over, leaves ovate-orbicular, 7-9-nerved, apex entire to 1/5 bifid    a. Bauhinia bidentata bidentata
4b.   Hypanthium thick, 10-12 mm, buds coppery silky hairy, ovary laterally glabrous, leaves broadly ovate, 5-7-nerved, apex entire to 1/3 bifid   
f. Bauhinia bidentata monticola
5a.   Leaves entire, (broadly) ovate, apex acute to acuminate, buds ferruginous hairy, often with 2 ridges on each sepal    d. Bauhinia bidentata fraseri
5b.   Leaves broadly ovate, emarginate to 1/3 bifid, rarely entire, buds coppery silky hairy    f. Bauhinia bidentata monticola
6a.   Bracts narrow lanceolate, 3-4 mm, bracteoles filiform, 1-2 mm, leaves ovate
c. Bauhinia bidentata cornifolia
6b.   Bracts ovate-elliptic, 4-5 by 2 mm, bracteoles lanceolate, 1-2 mm, leaves ovate-orbicular    e. Bauhinia bidentata gracilipes

a. Bauhinia bidentata Jack var. bidentata (Bauhinia bidentata bidentata )
Morphological description (bident v. bident Bauh Reinwf20 )
Leaves ovate-orbicular, usually shallowly bifid to l/5 bifid, 7-9-nerved.
Flowers: buds hairy. Petals distinctly short-clawed, claw c. l-2 mm. Hypanthium 10-20 mm. Ovary and stipe hairy all over, hairs often appressed. Stamens with the filaments hairy and with less swollen base than var. gracilipes, often subulate, 3-5 mm.

Malesia: Malay Peninsula (Penang I., where it seems to be common, and one collection from Perak). There is a collection from the Nicobar Islands in C.

Mainly a lowland species.

Vernacular names
Akar katup-katup, Dedaok, Sekoyah, Dauh nasi (all Mal. Pen.); Pride of Selangor (English).

1. The type of Bauhinia bidentata is Jack's plant represented by a specimen in E, a part of the protologue is found in Jack's handwriting on this sheet. De Wit (l. c. 497), evidently not aware of this, designated a neotype in C, collected in 1822 by Wallich (s. n.) in Penang. As Jack's specimen has been found this has to be accepted as the lectotype or even holotype.
2. For discussion of Phanera bicornuta Miquel (bicornuta Bauhinia FT5 ) see under Bauhinia integrifolia.

b. Bauhinia bidentata Jack var. breviflora (Ridl.) K. & S. S. Larsen (Bauhinia bidentata breviflora )
Morphological description
This variety is close to var. bidentata but deviates in the following characters: Leaf lamina from suborbicular to broadly ovate; apex usually emarginate rarely acute-subacute. Flower buds glabrous or glabrescent. Petals with indistinct claw. Ovary shaggy-hairy along suture only.

Malesia: all over the Malay Peninsula.

Mainly a lowland plant.

1. Prain, (1897: 187), recognized two closely related species, Bauhinia bidentata and B. cornifolia; in the former the ovary is described as sparsely pubescent, in the latter as densely rusty downy; some of the specimens he quoted under cornifolia, however, have an ovary apparently similar to the type of bidentata; some of the specimens he quoted under bidentata have a sparsely pubescent ovary except Wallich 5778 from Penang, which has the ovary densely hairy as the type of B. bidentata . Larsen & Larsen (1996: 509) have, therefore, reestablished var. breviflora to acomodate part of his B. bidentata.
2. De Wit, (1956: 495), uses the length of the filaments of the fertile stamens to separate his taxa, Larsen & Larsen (1996: 509) found that this character is not reliable as in the same flower the filaments may have different length.
3. Some collections from Selangor, e. g. J. C. 1583, have unusually larger leaves, up to 14.5-12 cm, and also larger infloresecences and flowers, the filaments are, however, hairy. Possibly these collections represent a local ecotype.

c. Bauhinia bidentata Jack var. cornifolia (Baker) Bennnett (Bauhinia bidentata cornifolia )
Morphological description (bident v. cornif Bauh Reinwf20 )
Deviates from var. bidentata by having entire leaves, filaments thick towards the base, glabrous, rarely glabrescent. From var. gracilipes it deviates by the ovate leaves, the bracts being narrow lanceolate, 3-4 mm, and the bracteoles filiform, 1-2 mm.

Malesia: Malay Peninsula.

Mainly in lowland forest.

d. Bauhinia bidentata Jack var. fraseri (de Wit) K. & S. S. Larsen (Bauhinia bidentata fraseri )
Morphological description (bidentata Bauhinia fl 256025 ;bident v. fraseri Bauh Reinwf20 )
Leaves entire, ovate-elliptic with truncate to cordate base, apex acute to acuminate, rather small, mostly 4-6 cm long, 3.5-5 cm broad, rarely longer; leaf undersides ferrugineous pubescent. Bracts and bracteoles longer than in the other varieties, 7-10 mm and 3-5 mm respectively; pedicels shorter giving the whole inflorescence a more condensed look. Hypanthium 5-10 mm. The indumentum of the floral parts is densely ferrugineous and the buds usually with two ribs on each sepal; on the young bud this character is, however, not always as clear as it seems from de Wit's description.

Malesia: Malay Peninsula (Cameron Highlands, Mt Mengkuang and Perak, Mt Kebau, Fraser's Hill, and probably other high mountains in the area).

Mountain species found usually above 1000 m.

e. Bauhinia bidentata Jack var. gracilipes (Merr.) K. & S. S. Larsen (Bauhinia bidentata gracilipes )
Morphological description
Leaves vary from small to large, broadly to narrowly ovate with obtuse, truncate or cordate base, up to 10 by 7 cm. The inflorescence is open, ferrugineous; bracts ovate-elliptic; pedicels 20-23 mm. Hypanthium 1 7-25 mm. Most characteristic are the filaments being glabrous with a swollen base.

Malesia: N Sumatra.

Mainly restricted to the lowlands.

f. Bauhinia bidentata Jack var. monticola (Ridl.) K. & S. S. Larsen (Bauhinia bidentata monticola )
Morphological description
This variety is close to var. fraseri but the leaves are broader, the apex entire to bifid to 1/3, with the tip of the lobes acute to acuminate, slightly falcate, leaf underside coppery puberulous. Buds smooth. Hypanthium thicker than in var. fraseri, and filaments much longer.

Malesia: Malay Peninsula.

Mountain forest about 1500 m altitude.