Archidendron borneense (Benth.) Nielsen, Opera Bot. 76 (1984)

Latin for 'from Borneo'.

Synonyms
Abarema borneense (Benth.) Kosterm.
Feuilleea borneense (Benth.) O.Kuntze
Pithecellobium borneense Benth.

Description
Shrub or small tree to 12 m high, 24 cm in diameter. Sometimes with small, narrow buttresses or stiltroots to 60 cm high. Bark smooth, grey or chocolate-brown, flaky, mottled with small, raised lenticels; inner bark pale red; sapwood brown to white. Branchlets terete or c. angled by ridges decurrent from the leaf-scars, scarcely puberulous by patent hairs, glabrescent. Leaves: rachis (3-)6- 10.5(-12) cm, puberulous, gland strongly raised, circular and concave, rarely linear-oblong with a central depression, c. 2-4 mm long; pinnae 1 or 2 pairs, 2-13 cm, puberulous; petiolules 2-5 mm, puberulous; leaflets (1-)2-5 pairs per pinna, opposite, coriaceous, drying grey-green to dark brown, equal-sided to very unequal-sided, usually obliquely ovate, obovate, broadly elliptic, or subtrapezoid (-lanceolate) 5-18 by 2.5-10 cm, base broadly cuneate to rounded, apex acuminate(-caudate), upper surface subglabrous with puberulous main vein, lower surface subglabrous with a few scattered hairs on the major veins and margins only; principal lateral veins 7-14(-20) per leaflet-half, parallel, oblique, straight; reticulation prominulous or prominent on both surfaces. Inflorescences terminal and axillary at the distal leaves, puberulous, consisting of pedunculate umbels aggregated into panicles to c. 40 by 50 cm; umbels consisting of c. 4-7 flowers, pedicels to 4 mm; floral bracts ovate elliptic, acute, c. 0.6 mm, puberulous to sericeous. Flowers pentamerous, bisexual. Calyx greenish yellow, cup-shaped, 1-2 mm, appressed puberulous or sericeous; teeth deltoid, to 0.2 mm. Corolla cream, funnel-shaped, 5-7 mm, appressed puberulous or sericeous; lobes ovate to ovate-elliptic acute, 2-3 mm, sometimes reflexed. Stamens cream, to c. 20 mm, tube equalling the corolla tube or shorter. Ovary solitary, densely puberulous. Pod reddish to orange both outside and within, curved into a circle before dehiscence, densely spirally contorted after dehiscence, chartaceous-coriaceous, c. 3.5 cm in diameter, valves c. 1 cm wide, slightly sinuate between the seeds, glabrous or subglabrous, veins inconspicuous, dehiscence first along the ventral suture. Seeds black, ellipsoid, compressed, c. 9 by 7 by 4 mm. [from Flora Malesiana]

Ecology
Lowland freshwater swamp, peat-swamp forest, heath forest, a few records from low mossy forest on sandstone ridges and peaks; altitude 0-1020 m.

Distribution
Sumatra and Borneo.

Local names
Borneo: Jiring paya, Kodingkang, Petai belalang, Tambarayung.