Colony Form:Large, bushy and often highly branched; usually to 60 cm tall, sometimes to 1 m.
Axis:Black, slightly compressed.
Branches:Flat, with 3-4 flaps or flanges producing a “Y” or “X” cross section. Branch width 3-6 cm; tapered from the base and often twisted; tips long and thin, pointed or flattened.
Apertures:Polyps emerge from a common groove along branch edges.
Mucus:None.
Color:Dark purple, purple or with purplish tints; occasionally olive brown, gray, yellow or a combination of yellow and purple. Purple, dark pink, yellow, or a combination when dried.
Sclerites:Polyp armature: small, blunt rods with few weak bumps or thorns, to 0.08 mm long, the largest often with slightly swollen ends. Body wall: stout spindles with large simple to complex tubercles, to 0.18 mm long; scaphoids (curved sclerites) often with blunt, finely tuberculate ends, to 0.14 mm long; ornamentation of scattered simple to complex tubercles and almost smooth convex surface.