Mallotus penangensis Mull.Arg., Linnaea 34 (1865)
Named after 'Penang', a province in Malaysia.

Synonyms
Mallotus echinatus Elmer, Mallotus leptophyllus Pax & K.Hoffm., Mallotus papuanus var. glabrescens Pax & K.Hoffm., Mallotus papuanus var. intermedius Pax & K.Hoffm., Mallotus penangensis var. grandifolia Ridl., Mallotus pseudopenangensis Pax & K.Hoffm., Mallotus sarawakensis Pax & K.Hoffm., Mallotus tenuipes Airy Shaw, Mallotus xylacanthus Pax & K.Hoffm.

Description
Sub-canopy tree up to 28 m tall and 35 cm dbh. Stipules ca. 6 mm long. Leaves opposite, but one of each pair stipule-like and easily overlooked, simple, penni-veined, glabrous, sometimes with hairy domatia in secondary vein axils. Flowers ca. 4 mm diameter, white yellow, placed in racemes. Fruits ca. 13 mm diameter, green-red, 3-lobed, spiny, dehiscent capsules.

Ecology
In undisturbed mixed dipterocarp, sub-montane and keranga forests up to 1333 m altitude. Mostly on hillsides and ridges with sandy soils. In secondary forests usually present as a pre-disturbance remnant tree.

Uses
Firewood and house construction.

Distribution
Nicobar Islands, Thailand, Peninsular Malaysia, Sumatra, Borneo (Sarawak, Brunei, Sabah, West-, Central- and East-Kalimantan), Philippines, Celebes, Moluccas, New Guinea.

Local names in Borneo
Enserai.