Siderastreidae is a family of colonial, reef building stony corals. Members of this family include symbiotic algae in their tissues which help provide their energy requirements. The World Register of Marine Species lists 7 genera within this family: Anomastraea, Coscinaraea, Craterastrea, Horastrea, Psammocora, Pseudosiderastrea, and Siderastrea.
Corals in this family vary in form and include massive, thickly encrusting, columnar, and irregular forms. Corallites are linked by flowing septae (walls) that have granular margins and that are fused in the center to give fan-shaped groupings. The corallites do not project from the surface of the coral and have ill-defined septae.