Characters: Colonies are irregular clumps of fine branchlets arising from a solid base. Radial corallites are appressed, with small nariform rounded openings. Colour: Uniform sky-blue (which may photograph pink), cream or brown. Similar species: Acropora nana, which has tubular appressed radial corallites with larger, not nariform openings. Habitat: Upper reef slopes exposed to strong wave action. Abundance: Usually uncommon.