It is a native shrub or small tree with male and female flowers on separate trees. It has a slender trunk and hairless branches or branchlets. It’s widespread in both the North and South Islands in lowland to the mid-montane forest in wet and shaded areas, often around creeks where it can grow to 6 metres high. It is common on alluvial soils and often abundant in bush remnant regrowth after fencing. It can be epiphytic on tree fern trunks.
It has the largest leaves (15 cm long or more) of any New Zealand coprosma. The oval leaves have a raised midrib on the upper surface and there are domatia on the underside. The leaves have a distinct vein pattern often there is a mottled appearance on the leaf’s top surface.
C. grandifolia produces ripe orangey-red drupes between February and May, and then flowers again during spring.
The tree’s inner bark is a vivid yellow/orange colour and was used as a dye by the early Maoris. The prepared bark was an important source of topical medicine for the Maoris.