Colonies are flattened, helmet- or dome-shaped. Corallites are subcerioid or have short, shallow valleys 8-20 millimetres wide, separated by thick walls. Tissue over the septa is usually distinct in colour and/or texture from tissue over the costae. Septa and costae are sturdy, with large blunt teeth.
In north-west Australia, colonies are a uniform blue-grey or valleys may have concentric cream and green colours. In south-east Asia colonies have a much wider range of colours including bright red, yellow and green.
Lower reef slopes protected from wave action.