Colonies are massive, the surface being flat or consisting of an irregular series of mounds or short columns. The coenosteum is covered with papillae which are usually elongate on mounds and short on flat plates. Thecal papillae are always present, those around corallites on mounds being relatively elongate. Thecal papillae are longer than coenosteum papillae, and may form a ring around corallite openings.
Usually bright or dark green, sometimes cream, brown, blue (which may photograph purple) or pink.