Common Name(s): Swollen knob candelabrum
Colony Form: Bushy or candelabrum, with long branches usually dividing near colony base; to 7-30 cm tall.
Axis: Cylindrical in cross-section.
Branches: Dense, upright, thick branches, 5-10 mm across, to 30 cm long.
Apertures: Crowded, conic to tube-shaped with slightly upturned lower lip, ~2 mm long but not longer than branch diameter, slightly compressed in cross section. Projecting calices around branches produce a knobby appearance. Bushy colonies have medium and large calices.
Color: Beige, dark yellow to ochre, and occasionally purple. Dries brownish to tan. Light brown polyps.
Sclerites: Tentacular armature with rods to 0.17 mm long. Axial layer: sharp deeply purple spindles (0.16-0.4 mm long, 0.04-0.08 mm wide). Middle layer: ornamented spindles to 2 mm long, 0.38 mm wide (5-8 times longer than wide). Surface layer: dense torch-like clubs to 0.22 mm long.
Habitat: Exposed or semi-exposed reefs to 20 m depth.
Distribution: Bahamas, South Florida, and throughout the Caribbean Sea.
Notes: Highly variable colony form.