Dictyota dichotoma

Thallus flat, creeping and erect, bushy, 10-15 cm high, pale brown to dark brown. Branching regularly dichotomous, forking at angles 15-45º. Branches strap-shaped, 3-15 mm wide, almost of equal width or gradually decreasing in width towards apices, with entire margins оr sometimes proliferous, with blunt or emarginated apices. In transverse section blade 140-165 μm thick; cortical cells squareroundish, densely pigmented, medullar cells rectangular, slightly longitudinally elongated. Surface hairs in tufts. Tetrasporangia tetrahedrally divided, in groups, on both surfaces of thalli. Antheriadia and oogonia develop in oval or linear longitudinally elongated sori; antheridia cylindrical or clavate, 18-24x27-30 μm; oogonia obovate, 50-60x65-80 μm. Growing on hard substrate, epiphytic on larger algae and on seagrass leaves, in lower intertidal to subtidal, exposed to moderate wave action.

Worldwide, from Arctic to Antarctic. Countries of the Asia-Pacific Region: Japan, China, Vietnam, Thailand, Malaysia, Singapore, Indonesia.