Sargassum horneri

Thallus densely branched, leathery, bushy, 2-5 m high, yellowish-brown. Stalk twisted, ribbed, cylindrical. Main axis to 3 mm in diam., cylindrical with furrows, bearing primary long branches. Phylloids alternately pinnately deeply parted, with prominent midrib; with sharp teeth on the top of segments, develop in the lower and middle portions of thallus. Vesicles stalked, cylindrical, elongated (3-5 diameters long), crowned with pinnatifid leafletlike outgrowth, develop in upper portion of the thallus, on separate branchlets in alternate manner. Plants dioecious. Receptacles stout, simple, cylindrical gradually attenuating to acute apices: male receptacles more slender than female one. Holdfast discoid, lobed. Growing on rocks in lower intertidal to subtidal.

Countries of the Asia-Pacific Region.