Knema elmeri Merr., Unif. Calif. Publ. Bot. 15 (1929)

Diagnostics
Mid-canopy tree up to 36 m tall and 49 cm dbh. Stem with red sap. Stipules absent. Leaves alternate, simple, penni-veined, hairy below, whitish below. Flowers ca. 9 mm diameter, red-purple, placed in bundles. Fruits ca. 24 mm long, orange, hairy, dehiscent capsules. Seeds with almost undivided red aril.

Description
Tree 5-15(-36) m, sometimes with stilt-roots. Crown rounded; no buttresses; bark smooth, scaly, flaky, or cracky, hard; inner bark white, reddish, or red-brown; sapwood brown. Leaves glossy dark green above, silvery beneath.Twigs +/- angled, 2-4(-5) mm in diameter, at first with rusty hairs 0.1-0.2 mm long, glabrescent; bark grey-brown, tending to crack longitudinally, later on flaking. Leaves chartaceous, elliptic to oblong(-oblanceolate), 12-32 by 4-13 cm, base rounded to acute, apex acute-acuminate; drying greenish or light brown above, early glabrescent, lower surface with persistent, silvery to pale brown, dense interwoven hairs 0.1-0.2 mm long, silky to the touch; midrib sunken to prominent above; nerves 12-20(-25) pairs, (slightly) raised or flat above; venation distinct above; petiole 8-18 by 2-4 mm. Inflorescences: sessile, brachyblast simple or irregularly warted, up to 8 mm in diameter, in male 5-25-flowered, in female 2-7-flowered; flowers with dense pale brown to rusty hairs 0.1 mm long, perianth 3-lobed, red or purple inside. Male flowers: pedicel 7-14 mm long, bracteole subpersistent, about median; buds broadly ovoid to depressed globose, often +/- sagged at base, 3-4 by 4-4.5 mm, cleft nearly to the base, lobes 0.5-0.8 mm thick; staminal disc circular, distinctly convex in the centre, 2-2.5 mm in diameter; anthers 10-14, just sessile or stalked, horizontal, 0.3-0.6 mm, not touching; androphore 0.5-0.8 mm, clasped by the somewhat thickened perianth base. Female flowers: pedicel 1-2 mm long, bracteole about median; buds +/- ellipsoid, 6 mm long, cleft about halfway, lobes 1 mm thick; ovary ellipsoid, 3 mm long; style 0-1 mm long, stigma 2-lobed and each lobe again shallowly 2-3(-4)-lobulate. Fruits 1-6 per infructescence, obovoid to ellipsoid(-oblong), apex obtuse or shortly beaked, 2-2.5 by 1.1-1.6 cm, with rusty hairs 0.1-0.2 mm; dry pericarp 2 mm thick; fruiting pedicel 1-5 mm long. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp to sub-montane forests up to 1500 m altitude. Common along rivers and streams, but also on hillsides and ridges. Usually on rich clay soils, but also on sandy and limestone soils.

Distribution
Borneo.

Local names
Borneo: Dara-dara, Darah-darah, Erak, Kumpang.