Grateloupia ramosissima

Thallus cartilaginous, bushy, 5–8 cm high, greenish to dark-red. Main axes cylindrical, 1–1.5 mm diam. Branches of the second order cylindrical or flattened, tapering to the base and tops, 1–1.5 mm wide and 1–3 cm long. Branches last order flattened, 1–1.5 mm wide, 1–10 mm long. On transverse section cortex consist of 3–4 layers small oval cells, 4.5 μm long, 2.5 μm wide. Subcortical layer consist of roundish cells, 12–15 μm diam. Medulla loose, consist of long cells, 7.5–8 μm wide, 35–40 μm long. Cystocarps 150–225 μm diam., submerged. Tetrasporangia oval, tetrahedrally divided, 15–25 μm long, 27–30 μm wide. Attachment by small holdfast, to 1 mm diam. Growing on middle to lower intertidal rock, artificial substrate, exposed to moderate and strong wave action.

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