A small hydrocoral with blunt, slightly flattened branches in violet or purple, the tips frequently white. Colonies reach about 15 cm (6 in) and hang from the ceilings of overhangs and cave mouths, where the colour stands out against dark rock under a torch.
It shares the fire corals' family trait of a hard skeleton built by an animal that is not a true coral, and the pores are arranged along the sides of the branches rather than over the whole surface - the character that separates this genus from Millepora and Stylaster. The sting is present but mild, and the animal is small and out of the way, so it rarely troubles anyone. Lace corals are collected for jewellery where they are accessible, and the whole family is on CITES Appendix II along with the other skeleton-builders. Shade is a requirement rather than a preference: these colonies carry no symbiotic algae and take everything they need from plankton, which is why they thrive in exactly the places reef-building corals cannot.
- small violet or purple colony with blunt, flattened branches
- branch tips often white or paler than the base
- grows on the ceiling of overhangs and cave mouths, hanging down
- colonies up to 15 cm across
