Small colonies are cushion-shaped or low domes or are irregular. Large colonies, which frequently exceed 5 metres across, are columnar or massive. Corallites are of mixed sizes, usually less than 10 millimetres diameter with numerous septa reaching the corallite centre. Tentacles are usually extended during the day.
Usually green, grey, red or brown, commonly with tentacles and septa of contrasting colours. Tentacles often have conspicuous white tips.
Reef environments protected from strong wave action.
Common in a wide range of habitats and may be a dominant species on inshore fringing reefs.