Pillar coral forms an encrusted base from which grow vertical cylindrical, round-ended columns.

The corallites from which the polyps protrude are smaller than 1 cm (0.4 in) in diameter and arranged in shallow meandering valleys with low ridges in between.

[5] Pillar corals are found in the warmer parts of the western Atlantic Ocean and the Caribbean Sea.

In sunlight these undergo photosynthesis and most of the organic compounds they produce are transferred to their host, while they make use of the coral's nitrogenous wastes.

[6] These algae give the coral its brownish colour and restrict it to living in shallow water into which the sunlight can penetrate.

[4] Each pillar coral clonal colony is either male or female, an evolutionary life history strategy described as gonochoric.

This is because recruitment and survival rates of juveniles is low and this coral is particularly susceptible to both bleaching and white plague disease.