Codium cylindricum

Thallus spongy, large elongated, usually 0.6-1 m long (sometimes 4-5 m), light or dark green. Branching dichotomous, sometimes trichotomous. Branches cylindrical or slightly compressed, becoming gradually slender above, with blunt apices, (2.5–)5.5-10 mm in diam., thallus commonly broader at branch forks. Utricles large, cylindrical, clavate, 850–2000 μm long, 200–500 μm in diam., with truncate apices, giving a granular appearance to the thalli. Hairs and hair scars abundant. Gametangia ovoid or elliptic, 220–310 μm long, 110-130 μm broad. Attachment by broad discoid holdfast. Growing on stones, rocks in the low intertidal and upper subtidal zones (to 2 m depth) of calm shores.

Asia (China, Japan, Korea, Taiwan); South-East Asia (Philippines, Vietnam).