Colonies are mostly arborescent, often with highly fused main branches. Main branches often curve away from each other and typically taper. Sub-branches are numerous, irregular in size and also taper. Axial corallites are thick walled but have small openings. Radial corallites are sometimes arranged in rows, are irregular in size, the larger projecting outwards with wide square-shaped openings.
Many colours, most commonly blue (which may photograph pink) or cream. Axial corallites are frequently yellow.
Upper reef slopes, especially where exposed to turbulence.