Melicope simplex is an endemic shrub with divaricating branches bearing small, round leathery leaves. Found throughout New Zealand in the margins of coastal and lowland forests.
Juvenile stages have much smaller leaves often divided into three leaflets. Adult leaves are small, thick, leathery and nearly circular with margins that have shallow rounded teeth. The underside of the leaves has visible oil glands. The leaves when crushed have an aromatic citrus smell.
Melicope simplex develops greenish-white flowerheads in spring followed by tiny black seedheads. Like many New Zealand natives, it has a divaricating juvenile form which can be confused with some small-leaved coprosma species like Coprosma rhamnoides. However, it is actually a member of the citrus family, Rutaceae. Also, the flowers of Melicope simplex and its dry wrinkled capsules for fruit are quite different from small-leaved coprosmas whose fruit is more like a fleshy berry. In addition to these obvious differences, the somewhat flattened leaf-stalk of Poataniwha has a “joint” across it.
Poataniwha may have difficulty thriving and will drop leaves without ample sunlight. Grows on both hillsides and poorer drained flat land. Usually under trees. Pollinated by insects and seed drops near the parent tree.