A classic brain coral, forming hemispheres which may reach 1 m across, though usually smaller. Some colonies are columnar, with heights 3 or 4 times their width.

Septa are large, thick and even, usually all the same size and lack spines. A ribbon-like collumella is usually clearly visible.

Colour is usually cream, with greenish and brown tints. Tentacles may be visible in daytime (but are smaller than those of Dendrogyra with which columnar forms could be confused).