Dysoxylum pachyrhache Merr., Univ. Calif. Publ. Bot. 15 (1929)

Latin for 'thick stalk or rachis'.

Synonyms
Epicharis pachyrhachis (Merr.) Harms

Diagnostics
Mid-canopy tree up to 32 m tall and 62 cm dbh. Stipules absent. Leaves alternate, compound, leaflets penni-veined, usually densely hairy below. Flowers ca. 12 mm diameter, white-yellow, placed in racemes. Fruits ca. 100 mm diameter, yellow-orange-red, capsules.

Description
Tree to 32 m with clear bole to 10 m, 62 cm diam., sometimes with short buttresses. Bark smooth with large corky lenticels, chocolate brown, to superficially fissured and finely cracking; inner bark bright orange, granular; sapwood pale brown; heartwood brown. Crown with sparse branching, open. Twigs stout, angled with cicatrices, greyish brown with bright brown lenticels, densely tomentose when young. Leafy twigs c. 10-15 mm diam.; buds stileto-like. Leaves to 1 m long in terminal spirals; 2-4-jugate with terminal spike or its scar, petiole 10-16 cm, terete to flattened adaxially, +/- densely brown tomentose, weakly swollen at base, leaflets +/- alternate, 12-25 by 7-12 cm, elliptic, +/- coriaceous, glabrous except on midrib adaxially, softly pubescent abaxially, bases somewhat asymmetric, acute to rounded, costae 15-18 on each side, spreading, inarched but not looped at margin; petiolules 5-11 mm. drying dark brown, weakly swollen. Thyrses to 8 cm long, usually much less, subspiciform, with congested branchlets of subsessile weakly scented flowers, axillary, supra-axillary in axils of leaves or cicatrices; axis 4-6 mm diam., densely pubescent. Calyx 3-4 mm long. 5-6 mm diam., shallowly cupular, densely pubescent without, pale brown, margin irregularly 4-lobed. Petals 4, 8-9 by 3 mm, densely pubescent without, creamish. Staminal tube glabrous, margin +/- crenate; anthers 8, c. 1.5 mm long, narrowly oblong, inserted within the tube. Disk c. 2-3 mm tall, glabrous, margin obscurely crenulate. Ovary 4-locular, densely adpressed pubescent; style adpressed pubescent at base; stylehead subcapitate c. 1 mm diam., with a basal annulus and impressions of stamens. Capsule solitary or in groups of 2 or 3, 5-8 cm long. c. 5-8 cm diam., subpyriform, glabrous when ripe, orange-red, stipe 1-1.5 cm, pericarp pale along sutures, to 1.5 cm thick, ochreous within. Seeds c. 2.5 cm long, orange-segment-shaped with creamy laticiferous (?) sarcotesta. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp and sub-montane forests up to 1600 m altitude. On hillsides and ridges with sandy to clay soils.

Distribution
Borneo.

Local names
Borneo: Injualang, Lantupak, Peleh manuk, Segera.