Characters: Colonies are thick corymbose to encrusting plates. Branchlets are short and thick and may be almost encrusting where colonies are exposed to strong wave action. There are usually several axial or incipient axial corallites per branchlet. Radial corallites are appressed, with thick flaring walls and are arranged in a rosette. Colour: Colonies are a mixture of colours, blue, mauve, purple and grey being the most common. Similar species: Acropora anthocercis exposed to strong wave action is distinctive; colonies in more protected environments are more like other species including A. hyacinthus, which has smaller and less appressed radial corallites. Acropora willisae also has multiple axial corallites per branchlet but has tubular radial corallites not in a rosette. See also A. appressa, A. desalwii and A. parapharaonis.Habitat: Upper reef slopes exposed to strong wave action. Abundance: Sometimes common.