Colonies are primarily composed of highly fused horizontal branches. These may form tables over 3 metres across or plates with a side attachment. Central parts of colonies may be almost solid. Most colonies, especially peripheral parts, are open branched. There may be few, if any, upturned branches. Corallites are irregular in length and tubular to rasp-like.
Shallow reef environments exposed to strong wave action.
Sometimes common, especially in the western Indian Ocean.