Characters: Colonies are massive, usually less than 300 millimetres across. They sometimes occur as free-living mobile balls. Corallites are rounded, deep, usually irregular and 2.5-3 millimetres diameter. Septa are in three clearly defined cycles. Columellae consist of one or a few granules.
Colour: Uniform light browns.
Similar Species: Siderastrea stellata.
Habitat: Shallow reef.
Taxonomic Note: The type species of Siderastrea de Blainville, 1830.