Tristaniopsis whiteana (Griff.) Peter G.Wilson & J.T.Waterh., Austral. J. Bot. 30: 440 (1982)

Synonyms
Tristania motleyi Ridl.
Tristania sumatrana Miq.
Tristania whitiana Griff.
Tristania whightiana Duthie [spelling variant]
Tristaniopsis whiteana subsp. whiteana

Diagnostics
Large tree with peeling, smooth, whitish bark. The stalked leathery leaves alternate and measure 7-20 cm in length by 2-5.5 cm in width. Its tiny flowers are about 5 mm wide. They have white petals and reddish sepals. Flowers are borne on a branched flowering shoot measuring 5-7.5 cm wide. It is insect pollinated. Its fruits are small, about 2.5-4 mm wide. Its fruit contains from one to many seeds. They are thin, thinly membranous, straight or curved.

Description
Canopy tree, occasionally shortly emergent tree to c. 45 m high, to 1.5 m diameter, with concave rounded buttresses; bark at first white to light greenish grey with occasional hint of very pale orange, smooth, later peeling in scroll-like strips; older unpeeled bark evenly pale grey-dull light olive; peeled bark scrolls pale to dark grey with mauve-brown patches; inner bark whitish; sapwood yellowish. Leaf beneath, rachis, flower bud fruit sparsely or densely more or less persistently grey-brown puberulent, or sometimes glabrous. Twigs c. 2 mm thick apically, slender, round, glabrous, smooth eventually thinly peeling. Leaves alternate, shiny fresh green when alive, drying rich dark olive-brown glistening beneath, oblong to lanceolate, 13 x 4 (7.3-17 x 2.5-4.5) cm, thinly leathery; base narrowly wedge-shaped, stalk distinct, (0.5-)0.8(-1.2) cm long, slender; apex sharply acute; main veins subequal, (54-)68(-92) pairs, very many, dense, slender, slightly but distinctly raised above and below; intramarginal vein to 1 mm within margin. Cyme to 10 cm long, to 5-branched, with long slender rachis. Flower cream with yellow stamens; bud c. 1.5 x 1 mm; pedicel c. 1 mm; calyx minutely warty, unribbed, lobes c. 0.5 x 1 mm; petals c. 1.5 mm; stamens 3 per cluster opposite each petal, filament c. 1.5 mm, anther c. 0.2 mm. Capsule c.4 x 3.5 mm, ellipsoid; seeds many, c. 0.4 x 0.2, elliptic. [from Tree Flora of Sabah and Sarawak]

Ecology
The paradigmatic late successional tree of landslips on the steep inland hills. Locally abundant also in secondary forest and river banks from the lowland to upper dipterocarp forest, to 1500 m on Kinabalu; generally in dipterocarp forests on mostly clay soils, but on sandy soils and the transition to kerangas in W. Sarawak.

Uses
The tree is harvested from the wild for its timber, which is used locally. The wood is hard and heavy It is used locally for building houses. The heartwood is generally reported to be resistant to attack by decay fungi and termites. It is used for flooring, pallets, heavy construction, specialty items (pulleys, rollers, bearings, sheaves, tool handles).

Distribution
Peninsular Malaysia, Sumatra, Borneo.

Local names
Borneo: Selunsor.