Coprosma wallii is a rare, robust, evergreen, densely branched shrub or small tree 2–5 m tall. The inner bark of the trunk, when scratched with a fingernail, will show a bright orange to almost a blood red colour while other species have green or yellow inner bark. It is a dense divaricating plant with small grey/bronze leaves.

Coprosma wallii produces a multitude of distinctive, small, fleshy fruits which are dark blue-black, dark red and sometimes white. These have seeds that are distinctive as they are nearly spherical; nearly all other New Zealand Coprosma species have seeds markedly flattened on one side. C. wallii is found in only a few localities in the North Island and few sites in Western Nelson at an altitude of 10–850 m. Most sites presently known are on Banks Peninsula, in Westland, and in Southland. Information below courtesy of Landcare Research