Knema percoriacea J.Sinclair, Gard. Bull. Sing. 18 (1961)
Latin for 'very tough or leathery', referring to the leaves.
Mid-canopy tree up to 33 m tall and 49 cm dbh. Bark of trunk rather smooth, fissured, scaly,
or flaking; living bark inside red-brown or pinkish; wood usually white, sometimes reddish,
or red brown. Leaves glossy dark green with whitish midrib above, glaucous with yellowish green
midrib beneath. Flowers with yellow to rusty indumentum. Fruits ellipsoid or round, with
yellowish or rusty indumentum.
Tree 5-25(-33) m. Twigs sometimes faintly angled, 3-6 mm diameter, at first with pale to
dark brown hairs 0.5-2 mm long, late glabrescent; bark smooth or striate, then usually
slightly to distincly longitudinally cracking, and flaking. Leaves chartaceous or coriaceous,
(oblong- )lanceolate, 12-40 by 2.5-9(-15) cm, apex subobtuse to acute(-acuminate), base
attenuate to rounded, drying olivaceous or brown above, lower surface glabrous, not or
but little papillate, with scattered hair scars (lens!); dots absent; midrib much raised
above; nerves 15-25 pairs, raised above; venation distinct; petiole sometimes +/- pulvinate,
late glabrescent, 7-25 by 3-8 mm. Inflorescences: peduncle up to 2 mm long, brachyblast
simple, warted, or 2-furcate, up to 15 mm long; in male 10-20-flowered. female up to
15-flowered; flowers with light brown or dark brown hairs 0.5-2 mm long, sometimes
partly deciduous; perianth 3-lobed, red inside. Male flowers: pedicel 3-4.5 mm long,
bracteole persistent, at or above the middle; buds depressed (globose-)obovoid, (3.5-)
4-5.5 by (3.5-)4-5.5 mm, cleft 2/3-3/4, lobes 0.5(-1) mm thick; staminal disc circular
or subtriangular, flat, 2-2.5 mm diameter; anthers 10-18, shortly stiped or subsessile,
half-erect or curved upward, 0.3-1 mm long, not or but little touching; androphore 1-1.5
mm, finely striate. Female flowers: pedicel 2-4 mm long, bracteole subapical; buds
ovoid or ellipsoid, 6.5-8(-9) by 5-7 mm, cleft slightly over halfway, lobes 0.5-0.7 mm
thick; ovary subglobose, 3.5-4 mm diameter, stigma sessile. 2-lobed and each lobe again
8-10-lobulate or serrate. Fruits 1 or 2 per infructescence. (broadly) ellipsoid, sometimes
slightly flattened, 3-4.5(-5) by 2.5-3.5(-4.5) cm, with rusty hairs 1-2 mm long; dry
pericarp 4 mm thick; fruiting pedicel 2-3 mm long. [from Flora Malesiana]
In undisturbed mixed dipterocarp and keranga forests up to 700 m altitude.
Usually on hillsides and ridges, rarely on alluvial sites. On sandy soils,
sometimes also on clay soils.
Borneo: Kumpang, Mandarahan, Pendarahan.