Characters: Colonies are extensive flat plates which are solid except towards the perimeter which usually consists of highly fused irregular branches. They may exceed 2 metres across. Axial and radial corallites are not differentiated; all have sharp rims. Corallites at plate margins are mostly horizontal, those on upper plate surfaces are short, compact and upward facing. There is little or no development of corallites on the undersurfaces of plates.
Colour: Uniform dark grey.
Similar species: Acropora clathrata, which has less fusion of branches and inclined radial corallites. See also A. branchi.