Caulerpa webbiana

Thallus small, fine, 1.5–2.2(–5) cm high, grass-green to dark green, consisting of creeping, cylindrical stolons, to 400 μm diam., bearing fine branched rhizoids and erect branched axes. The axes bearing small, irregularly whorled, tough, spiny branchlets from all sides. Branchlets (pinnulae) 2–6 per whorl, ~500 μm long, 2–5 times dichotomously branched, cylindrical at base, flattened above with forked pointed apices. Rhizoids filamentous arising from creeping and erect axes. Growing in crevices on sandcovered rocks, dead corals, at low intertidal to upper subtidal.

Subtropics and tropics of Atlantic, Indian and Pacific Oceans. Asia (Japan, Taiwan), Pacific Islands, Spratley Islands.