Canistrocarpus cervicornis

Thallus bushy, 8-15 cm highs. Branching irregularly dichotomous. Branches near the base 3-4 mm wide, tapering slightly from the base upwards, 0.6-2.5 mm wide. Branch tips forked, acute, one of the forks shorter and spurlike. Segments between dichotomies 1.0-3.5 cm long. Margins entire. Thallus in transverse section 180-200 μm thick. Medullary colorless cells rectangular, 125-140x70-120 μm. Surface cells rectangular, 12-20(-30) μm wide, 30-40 μm long, in longitudinal rows. Surface hairs in tufts, scattered near central axis. Marginal rhizoids present, often in tufts, to 500-700 μm long. Attachment by fibrous holdfast. Antheridial sori multichambered, 75x100 μm, surrounded by pigmented paraphyses. Sporangia (50 μm diam.), scattered. Growing on rocks, epiphytic, in shallow waters.

Tropics and subtropics of Atlantic, Indian and Pacific Oceans.