Pternandra crassicalyx Maxwell, Gard. Bull. Sing. 34, 1 (1981)

Latin for 'thick or coarse calyx'.

Possibly a synonym of Pternandra rostrata.

Understorey tree up to 17 m tall and 24 cm dbh. Stipules absent. Leaves opposite, simple, tripli-veined, tertiary venation visible, glabrous to hairy below. Flowers ca. 12 mm diameter, white-bluish, placed in axillary bundles or solitary. Fruits ca. 10 mm diameter, blue-purple, berries.

In undisturbed mixed dipterocarp forests up to 900 m altitude. Usually on hillsides and ridges with clay to sandy soils. In secondary forests usually present as a pre-disturbance remnant tree.

Borneo (Sarawak, Brunei, Sabah, East-Kalimantan).

Local names
Borneo: Empulus, Okea, Puloh, Serih-serih, Siri-siri.