Laurencia nipponica

Thallus soft cartilaginous, solitary or aggregated, bushy, 15-30(-40) cm high, of pyramidal outline, purple-red to brownish, consisting of main axes (1-4 mm diam.) arising from entangled rhizoidal stolons. Branching (to 3-5 orders) irregular alternate, opposite to verticillate. Branches covered by short ultimate (determinate) branchlets, cylindrical (when sterile) and swollen (when fertile) with blunt or rounded apices. Sporangia embedded, in longitudinal rows near the top of terminal branchlets (converted into stichidia), subspherical, 65-85×84-123 μm, tetrahedrally divided. Cystocarps ovoid, 670-840(-900) μm diam., develop on sides of determinate branchlets. Attachment by disc-like hold-fast. Growing on rocks and stones in lower intertidal (often forming narrow belt on vertical rocks) and in upper subtidal (as separate individuals), in sites exposed to moderate and strong wave action.

In moderate to tropical seas of Pacific Ocean.