Characters: May form dome-shaped colonies over 3 metres across, composed of isolated subcolonies which are shaped like upturned hands. Colonies (or subcolonies) are digitate, with thick branches tapering to a small axial corallite. Colonies exposed to strong wave action have pyramid-shaped branchlets. Radial corallites are uniform in size and usually arranged in rows. Colour: Blue (which may photograph purple) or cream, usually with pale branch tips of contrasting colours. Similar species: Acropora humilis, A. globiceps, A. retusa and A. gemmifera. Habitat: Upper reef slopes. Abundance: Sometimes common in eastern Australia, usually uncommon elsewhere.