Sindora irpicina

Author: de Wit

Morphological description (irpicina Sindora BBGB18 f10 )
Tree up to 40 m high and 80 cm in diameter. Stipules caducous, not seen.

Leaves (3-)5-jugate; petiole 2.3-3.8 cm and rachis 7.5-19.5 cm long, slightly puberulous, glabrescent, or almost glabrous; petiolules very short, up to c. 6 mm, minutely puberulous, glabrescent. Leaflets coriaceous, elliptic, oblong-elliptic or rarely obovate, 5.4-10.5 by 2.1-4.8 cm; apex acuminate to attenuate; base obtuse, rounded, acute or slightly cuneate, often symmetric; upper surface glossy and glabrous; lower surfaces glossy, sparsely and minutely puberulous, glabrescent, sometimes almost glabrous except on the midrib.

Inflorescences paniculate, up to 16 cm long, lateral branches straight, 1-4 together, up to 4.5 cm long, both rachis and branches pubescent; bracts and bracteoles usually not present on dry specimens, rarely bracteoles observed on young flowers, lanceolate, up to c. 3 mm long, densely puberulous; pedicels 3-5 mm, densely puberulous.

Flower: Calyx lobes 4, lanceolate, 3.5-6 by c. 3 mm, unarmed, puberulous outside, densely appressed hairy inside. Petal 1, ovate, 5 by 3 mm, deeply concave to involute, outside densely puberulous in the lateral parts, inside glabrous, margin villose. Stamens: united basal parts of the filaments c. 1 mm high; free filaments and staminodes up to c. 10 mm, sparsely hairy in the lower half; anthers 2 (perfect) largest, ellipsoid, c. 0.35 mm long, the others much smaller. Ovary subsessile or very shortly stiped, ovate, c. 4 mm long, densely woolly, with many minute outgrowths, 3-5-ovuled; style up to c. 14 mm, involute or recurvate, hairy at the basal part; stigma small.

Pods black, on a stout peduncle (1-1.5 cm long), ellipsoid or oblong-ellipsoid, rarely slightly reniform, 11-14 by 5.5-8 cm, flattened, hard, covered with evenly spaced, numerous, slender, sharp spines (c. 3 mm), beak almost straight, 3.5-8 mm long, 1-3-seeded.

Seeds broadly suborbicular, c. 1.8 cm long and wide, smooth, on top of a large, reniform aril (c. 3 by 1.5 cm).

Malesia: Borneo (Brunei, Sarawak, Sabah, Kalimantan).

Habitat & Ecology
In lowland forests, often near the banks of brooks, on sandstone, sandy limestone, shales, sandy and volcanic soils, up to 700 m altitude. Flowering in May; fruiting in March, April, June, July, September, and November.

The present species can be easily recognized by:
1) leaves 3-5-jugate,
2) leaflets glabrous above,
3) the ovary densely woolly, with many minute outgrowths (to be observed with the dissecting microscope),
4) pods bearing scattered, evenly disposed spines,
5) the seed on a large, reniform aril.