Author: Bentham
Morphological description (wallichii Sind BBGB18f15 )
Tree up to 24 m high and 67 cm in diameter. Stipules foliaceous, subintrapetiolar, falcate, up to 15 mm long, acuminate, rounded auriculate at base, reticulate and finely puberulous on both surfaces, tardily caducous.
Leaves 3- or 4-jugate; petiole 1.2-2.5 cm and rachis 4.5-8.5 cm long, minutely puberulous, glabrescent, or sometimes glabrous in the upper half; petiolules very short or subsessile, up to c. 3 mm, puberulous, glabrescent, or glabrous. Leaflets coriaceous, elliptic-ovate or elliptic-oblong, ovate- or obovate-oblong, 4-10.5 by 2.5-5 cm, upper pair usually the largest; apex acute, subacuminate, obtuse, the very tip slightly notched; base obtuse or rotund, often more or less unequally sided; upper surface brightly glossy and glabrous, sometimes puberulous in the lower half or very minutely puberulous all over; lower surface rather dull and glabrous or densely pubescent.
Inflorescences paniculate, up to 24 cm long, lateral branches zigzagging, rather short, up to c. 4.5 cm long, both rachis and branches densely puberulous; bracts triangular, wider than long, up to 4 mm long and 7 mm wide, puberulous on both surfaces; bracteoles oblong or lanceolate, c. 4.5 mm long, puberulous on both surfaces; pedicels almost absent or very short, up to 4 mm, puberulous.
Flower: Calyx lobes 4, lanceolate, up to 9.5 by 3 mm, outside puberulous and bearing some distinctly spiny outgrowths often in the upper half, inside glabrous. Petal 1, elliptic or oblong-elliptic, c. 8 by 2-2.5 mm; outside woolly; glabrous inside. Stamens: 10 (9+1), united basal parts of the filaments very short; free filaments up to c. 10 mm, slightly hairy at the lower part; (fertile) anthers various in size, the 2 larger ones ovoid-ellipsoid, c. 3.5 mm long, the others smaller. Ovary sessile or shortly stiped, subrhomboid, c. 5 mm long, densely hairy, with many minute, spiny outgrowths, 2-4-ovuled; style up to c. 10 mm, recurvate, glabrous or sparsely hairy in the basal part; stigma terminal, small, capitate.
Pods on a very short peduncle, suborbicular, broadly obovoid or ellipsoid, 6-10 by 4-6 cm, flattened, both surfaces covered with close, hard, straight spines (up to c. 5 mm); beak curvate, c. 8 mm long; 1- or 2(or 3)-seeded.
Seeds suborbicular, c. 2 cm in diameter, on a larger aril (often broader than long).
Distribution
Malesia: Sumatra (E Coast, Jambi, Palembang, Riau Archipelago), Malay Peninsula, Borneo (Sabah, Kalimantan).
Habitat & Ecology
In lowland forests, on non-inundated sandy or sometimes clayey soils, sometimes near mangrove swamp, often below 100 m, sometimes up to 300 m altitude. Flowering in March, May, July, and October-December; fruiting in January, March, Augustus, and December.