Colonies are compact aggregations of fused upright branches, flat plates, or tiers of plates. Colonies exposed to wave action have extensive encrusting bases and may form solid plates several metres across. Upright branches develop on colonies in protected lagoons. Axial corallites and incipient axial corallites are small and similar. Radial corallites are thick walled, tubular and appressed, and usually have a wall on the outer side only.
Uniform green or brown.
Shallow lagoons and foreshores exposed to wave action.