Gelidiophycus divaricatum

Thallus cartilaginous, densely caespitose, 0.5–2 cm high, composed of creeping terete or subterete axes, (150)–250–400(–700) μm wide, bearing erect branches. Branching bipinnate, with opposite-alternate ultimate branchlets at right angles. The branchlets 200–500 μm wide, 0.2–3 mm long, with blunt or acute slightly inflated apices. In cross section, cortex consists of four layers of roundish cell gradually increasing in size toward the center. Medulla of colorless isodiadiametric cells, ~18 μm diam., the outer ones surrounded by small cells of rhizoidal filaments.
Cystocarps near to spherical, 450–650 μm diam. Sporangia elliptic (25–35×60 μm) or spherical, to 37 μm diam, cruciately divided, develop in rounded or expanded sori in terminal branchlets. Attachment by peglike holdfast to rocks.

Japan, Korea, China, Vietnam.