We extend special thanks to Philippe & Guido T. Poppe von Poppe Images, Marine Iconography of the Philippines Archipelago who provided this excellent photo.
Characters: This is usually an azooxanthellate species in the Mediterranean, but usually zooxanthellate on the American coast. Colonies are encrusting or nodular. Corallites are compact and slightly polygonal in outline. Septa are in two, alternating, cycles. Ten primary septa are fused with the columella. The second cycle is shorter but well developed.
Colour: Red, pink, grey or green, partly depending on the presence of zooxanthellae.
Habitat: Deep water.
Abundance: Rare except in caves.
Source: Corals of the World by Charlie J.E.N. Veron