Characters: Colonies are submassive, encrusting, nodular or columnar, columns being club-shaped. Corallites are subcerioid, closely compacted and angular in outline, with solid conical columellae. Usually ten septa are present and these are fused with the columella. The coenosteum is covered by fine spinules. Tentacles are usually extended only at night.
Colour: The oral disc is green or white, the coenosteum mottled brown and reddish-brown.
Similar Species: Madracis decactis which has relatively uniform branches and corallites.
Habitat: Most reef environments but especially turbid ones.