Petaloid Corals

Petaloid corals are easily identified from other families by the flower-like 'petaloid' pattern created by enlarged septa. Members of this family tend to be overlooked due to small colony size and drab coloration. Coscinararea has very large calices while Psammocora have very small ones.

Haleiwa Trench, Oahu, 80 feet	Au'au Crater, Hawaii, 140 feet
Haleiwa Trench, Oahu, 80 feet

Uncommon on walls at depths exceeding 100 feet, color is cream with large petaloid septa and dark centers. Typically forms a small plate with free edges. Hawaii & the Indo-Pacific.

Okoe Bay, Hawaii, 90 feet	Haleiwa Trench, Oahu, 80 feet
Haleiwa Trench, Oahu, 80 feet	Brown form, Haleiwa Trench, Oahu, 80 feet
Haleiwa Trench, Oahu, 70 feet	Haleiwa Trench, Oahu, 70 feet
Haleiwa Trench, Oahu, 70 feet	Haleiwa Trench, Oahu, 70 feet
Haleiwa Trench, Oahu, 70 feet

Rare on vertical walls in shaded areas deeper than 60 feet, it has a very rough surface and dark overall coloration, polyps sometimes appear whitish. Calices are crowded between raised petaloid septa and require close examination. Hawaii & the Indo-Pacific.

Puako, Hawaii, 25 feet	Puako, Hawaii, 25 feet
Honaunau, Hawaii, 50 feet	Branched form, Kapoho tidepool, Hawaii, 4 feet

Common encrusting species on vertical surfaces and the dead base of Finger Corals. Distinctive sandpaper-like granules cover the entire surface. Calices are located in meandering valleys and the basic color is dark greenish brown to gray. Rarely forms small knobby heads like that of Starry Coral.

Kaena Point, Oahu, 25 feet	Halona Blowhole, Oahu, 25 feet
Kahe Point, Oahu, 20 feet	Kahe Point, Oahu, 20 feet
Ke'ei, Hawaii, 25 feet	100 ft. Hole, Waikiki, Oahu, 80 feet
100 ft. Hole, Waikiki, Oahu, 80 feet	100 ft. Hole, Waikiki, Oahu, 80 feet

Uncommon on shallow vertical surfaces and often confused with Sandpaper Coral but lacks the characteristic sandpaper texture. Color is normally light brown and the deep columella is darker. Each calyx has sharp angular walls.

Kure Atoll, 6 feet

Kualoa, Oahu, 6 feet

Kualoa, Oahu, 6 feet

Small tan nodules with short irregular branches without sandy texture or raised septa. Calices very small and slightly depressed with petaloid appearance. Frequent on shallow reef flats with scattered sand pockets.

Uncommon on vertical walls and shaded locations. Very similar to P. nierstraszi but lacks sandpaper-like raised septa . Individual calices are located in shallow depressions.