P. dioica is a small dioecious evergreen tree, 7-10 m tall with a slender trunk (50-100 cm at the base) with many branches 1-2 m above the ground. The bark is pale silver-brown, smooth and shiny, and sheds strips 25-75 cm long. Leaves are borne in clusters at the ends of branches. Flowers are white and in branching clusters; berries are green when unripe, turning deep purple to glossy black when ripe. Leaves are 6-15 cm long, 3-6 cm wide, simple, opposite and aromatic when crushed. They are dark green on the upper surface and lighter green beneath. Flowers are structurally hermaphrodite, but functionally male or female. They are aromatic and 8-10 mm in diameter, with four rounded petals about 3-4 mm long, which are quickly deciduous. The stamens are numerous, 5 mm long (100 in male flowers, 50 in female flowers). The anther is cream coloured, the style white and 5 mm long, and the stigma is yellow. Fruits are round, drooping berries, 4-6 mm in diameter, green when unripe, turning deep purple to black when ripe. Fruits are aromatic on drying; dried unripe fruits are dark brown. The fruits consist of a thick pulp with two kidney-shaped seeds separated from each other by a membrane.