Laurencia tropica

Thallus caespitose, dendritic, rigid, bushy, 4-6(-15) cm high, with several erect axes densely tufted, light brown in color. Main axes cylindrical, ~1(-1.5) mm diam. Branching from all sides, irregular, alternate, or sometimes subverticillate, naked at the base, densely branched in the upper half. Ultimate branchlets cylindrical, 2-3 mm long (becoming shorter toward tips) with truncate apices. In transverse section, cortical layer composed of transversely elongated cells, ~20-25×32-37 mm, followed by larger, 35-37×37-45 mm toward to medullar cells, 37.5×45-60 mm. Axial cell ~22.5 mm diam. Lenticular thickenings in cell walls of the medulla rare. Sporangia tetrahedrally divided, located longitudinally, near apices of the ultimate branchlets. Cystocarps sessile, near to spherical, urn-shaped, with apical pore, ~600 mm across, arranged laterally near the apices of ultimate branchlets. Growing on rocks, in the lower intertidal pools of carbonate basis of reef, in upper subtidal of moderately to strong exposed shores.

China, Taiwan, Japan, Korea, Vietnam, Philippines.