Short knobbly branches, the main reef-builder of the eastern Pacific and the first coral to bleach when the water warms.
Branching cauliflower- or cabbage-shaped clumps up to about 30 cm high, forming aggregations several metres across. The branches are covered in irregularly placed wart-like bumps, which is the mark of the genus. The growth form is very plastic: open and finely branched in calm water, compact and stout on high-energy reef fronts. Greenish, pink, yellowish-brown or pale brown.
There is no reliable field separator within this group in the eastern Pacific, and the honest position is that it is identifiable to genus underwater and needs genetics beyond that. That matters here more than usual. A 2026 genomic study concluded that the species this entry is named for is not present in the eastern tropical Pacific at all, and that the corals there sort into three other species plus one resurrected in the same work. The Galapagos and Revillagigedo records are real but are pre-genetic identifications based on shape. Read this entry as the cauliflower coral complex rather than as a firm species.
It carries symbiotic algae and is extremely adaptable, living on exposed reef fronts, in lagoons, in mangroves and on wharf piles, most abundantly between 5 and 20 m and down to about 40. It hosts a wider range of algal partners than any other known coral, and it is the first coral to colonise after a disturbance and the main structural coral of eastern Pacific reefs.
The Galapagos and Revillagigedo records are published. The Cocos record could not be confirmed at species level and needs checking. The species is listed as endangered in a 2024 assessment, which is more recent than most sources say.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
