Sargassum denticarpum

Thallus tough, leathery, densely branched, to 1 m high, yellowish-brown. Main axis short, cylindrical, smooth, to 10 mm high, to 5 mm diam., bearing to five primary branches from the distal portion. Primary branches compressed, smooth, to 50 cm long, 5 mm broad at base and 3 mm at the distal portion, bearing secondary distichously arranged branches at intervals 5 cm. Phylloids elongateellipsoidal or linear-lanceolate, to 5 cm long, 2 cm broad, with asymmetrical base, short petiole and with acute apex. Margins irregularly dentate. Midrib distinct, evanescent or percurrent, sometimes spinose. Vesicles spherical or ellipsoidal, 8.5 mm long and 7 mm wide, apiculate, entire or with toothed wings at the margin or apex; shortly stalked. Stalk cylindrical or foliaceous, to 3 mm long. Cryptostomata distinct irregularly scattered on both surfaces of phylloids, vesicles and stalk. Receptacles compressed or triquetrous, to 4 mm long, 1 mm broad, furcated with acutely dentate margins. Holdfast conical or discoid, to 1.4 cm diameter. Growing on hard substrates in the lower intertidal to subtidal zones.

Vietnam.