Characters: Colonies are up to 30 cm across and consist of irregular branches composed of irregularly fused corallites which vary in size. Larger corallites have three cycles of septa. Primary septa almost reach the corallite centre where they plunge vertically. Third cycle septa are short. Septa are not as exsert as in other Galaxea species. There is no columella. Two subequal cycles of costae extend down the outer wall of all corallites, becoming submerged in the coenosteum. The surface of main branches is composed of smooth coenosteum. Tentacles are extended day and night.

Colour: Pale brown with white tentacle tips.

Similar Species: Galaxea astreata, which is never arborescent and has smaller corallites (which are sometimes exsert and may have lateral daughter corallites). See also G. acrhelia which has smaller corallites, is more distinctly branching, and has very exsert septa.

Habitat: Shallow protected reef environments.

Abundance: Uncommon.