Characters: Colonies are nodular, laminar or encrusting. Nodules are usually flattened in section and club-shaped. Corallites are widely separated and circular to angular in outline, with a solid conical columella. Usually ten septa are present and these are fused with the columella. The coenosteum has fine spinules which sometimes form a ridge between the corallites.
Colour: Pale to dark greenish-brown or yellowish-green with pale branch tips. Bluish-grey in Brazil. Oral discs are usually not distinctive.
Similar Species: Madracis mirabilis, which has similar corallites but has branches which are finer, circular rather than flattened in section, usually has tentacles extended during the day and is yellow.
Habitat: Usually occurs in shallow water, but also found in low light conditions.
Abundance: Sometimes common.