Hopea rudiformis Ashton, d. Bull. Sing. 31 (1978)
Latin for 'roughly-shaped'?

Note
The type specimen of this species is collected in Sungai Wain.

Description
Mid-canopy tree up to 36 m tall and 67 cm dbh. Stem with resin. Stipules dropped early. Leaves alternate, simple, penni-veined, conspicuous secondary veins. Flowers ca. 4 mm in diameter, white-yellow, placed in panicles. Fruits ca. 8 mm long, green, with rwo ca. 56 mm long wings, wind dispersed.

Ecology
In undisturbed mixed dipterocarp forests up to 200 m altitude. Usually growing on alluvial sites, but also present on hillsides. On sandy to clayey soils. In secondary forests usually present as a pre-disturbance remnant tree.

Uses
The timber is used.

Distribution
Borneo (Sabah, South- and East-Kalimantan).

Local names in Borneo
Damar batu, Damar jankar, Damar putih, Emang bakau, Putang lanan, Selangan jangkang.