Characters: Colonies are generally encrusting or form solid plates, occasionally becoming submassive. They have a flat or irregular surface and may be over 2 metres across. Corallites have long or short fine septal spines which seldom connect. Tips of polyp tentacles may be pointed or knob-like. Sometimes six large tentacles alternate with six small tentacles.
Colour: Usually uniform pale or dark brown, rarely green or other colours. Polyps sometimes have white tentacle tips.
Habitat: Protected upper reef slopes.
Abundance: Usually uncommon.
Taxonomic Note: A species complex.