Characters: Colonies are massive, forming boulders or domes, or are flat plates. Corallites are variable, but are usually conical and exsert. Long and short septa strongly alternate, with alternate septa joined to the columella.
Colour: Commonly green, brown, grey, or orange.
Similar Species: None.
Habitat: All reef environments, especially lower slopes.
Abundance: Common.
Taxonomic Note: A monospecific Atlantic genus, following significant taxonomic rearrangement of numerous other Atlantic and Indo-Pacific species into other genera.
Taxonomic References: Laborel (1969); Zlatarski and Estalella (1982); Amaral (1994); Veron (2000a); Budd, Fukami, Smith et al. (2012);
Identification Guides: Humann (2002);
