Codium adhaerens

Thallus spongy, smooth, lubricous, dark green to blackish, forming creeping, undulate (tighly adhering to the substratum) mats to 10 cm in diam. Utricles cylindrical, clavate, 70-140(-250) mm diam., 500-700 mm long, slightly constricted below apex. Apex rounded or flattened. Apical wall thickened with longitudinal striations. Hair scars (basal portions of hairs) 80-100 mm below apex. Gametangia fusiform, 50-75(-100) mm diam., 180-270 mm long, in the upper half of the utricle. Rhizoidal filaments 22-25 mm diam. Growing on hard substrate, often on vertical rocky walls, damaged corals, in the middle and low intertidal zone.

Temperate to tropical waters of Atlantic, Indian and Pacific Oceans.