Out of the two species under the genus Cotylelobium that occurs in Peninsular Malaysia, Cotylelobium melanoxylon or commonly known as resak is one of them. This species has been recorded in Gunung Arong FR (where a portion of its population occurs in High Conservation Value Forest), Jemaluang FR and Tenggaroh FR in northeastern Johor while in Sabah and Sarawak, several populations of this tree species occur in the network of Totally Protected Areas (Chua et al., 2010; Suhaida, 2013).

C. melanoxylon is a tall emergent tree growing up to 60 m in height and is considered a small tree with a girth of 1-3 m. It has a smooth bole and is brightly coloured like that of a Vatica when young. Its outer bark is pockmarked when young and becomes irregularly scaly when old. The inner bark is about 8 mm thick and is tinged purple-pink while the leaf is glabrous with ovate or elliptic-ovate shaped and has about 12 pairs of main veins (Suhaida, 2013).

Preferring dry, often sandy or loamy soils and moist podsol, this species inhabits lowland areas up to hill dipterocarp forests at altitudes below 400 m and in Kerangas (heath) forests on podsols. Populations of C. melanoxylon also often occurs not far from the coast (Suhaida, 2013).

This dipterocarp species is categorised as Endangered under the Malaysia Plant Red List due to land conversion and habitat loss (Chua et al., 2010; Suhaida, 2013).