Melicope lydgatei is a small shrub of the Rutaceae (rue) family that has leaves arranged oppositely or in threes. The glossy, papery leaves, which are 4 to 13 cm (1.6 to 5.1 in) long and 1.5 to 6.5 cm (0.6 to 2.6 in) wide, vary from lance-shaped to oblong. Flowers are usually functionally unisexual, with both unisexual and bisexual flowers growing on the same plant. Its aromatic, greenish white flowers are about 4 to 7 mm (0.2 to 0.3 in) long and arise singly or in clusters of two or three. The four-lobed capsules, which have sections fused for one-fourth to one-third their length, are between 14 and 22 mm (0.6 and 0.9 in) wide, and contain one or two glossy black seeds, about 5 mm (0.2 in) long, in each section. Both the exocarp and endocarp (outermost and innermost layers of the fruit wall, respectively) are hairless.