Elaeocarpus mastersii is a small or medium-sized tree, that can reach up to 24 m tall. It is distributed in Sumatra, Peninsular Malaysia, Singapore and Borneo. In Peninsular Malaysia, this species is known from all states where it grows commonly in lowland dipterocarp forest, usually by rivers, in freshwater or peat swamp forest. It can also be found in hill dipterocarp forest and upper montane forest, on granite- or quartzite- derived or sandy soil and occasionally in secondary forest or disturbed habitats from 65-2,000 m altitudes (Kiew et al., 2018).

Elaeocarpus mastersii has 1.1-1.8 mm thick twigs that usually hairy towards tips. The stipules are narrow-subulate, 1-3 mm long with some adpressed hairs on the back. Its leaves develop loosely towards twig tips or scattered. The racemes grow among current leaves at about 1-3 cm long. The flowers are 4-merous with obovate petals which narrowed in lower third but not narrow into a claw. Its sepals probably falling at the same time as petals and stamens. Its greyish-blue fruits (Nparks Flora Fauna, 2019) are ovoid to ellipsoid (Kiew et al., 2018).