Description:

Thallus brittle, spiny, wide spreading, to 25 cm high, color variable, brown, red-brown, green to yellow; branching irregularly radial, sparse. Branches cylindrical, 0.6-3.0 mm diam., with central polysiphonous core surrounded by heavy cortication; spur-like spines absent. Branchlets uniformly abundant, short, possessing spur-like spines; spines to 0.5 mm long; hair-like filaments in clusters, obscure, deciduous. Holdfast irregularly lobed, disc-like. Tetrasporangia in linear rows, 42-50 µm diam., 60-80 µm long, tetrahedrally divided, in short spine-like swollen branchlets. Spermatangial clusters disc-like, often present at base of sterile hair stalks. Cystocarps urn-shaped, 0.5-1.0 mm diam., solitary, in axes of spines.

Habitat:

Common: early colonizer on wood, pebbles or other organisms in calm waters; intertidal to 8 m deep.

Distribution:

Pacific Panama - New record for the eastern Pacific

Type Information:

Type locality: St Croix, US Virgin Islands

Classification:

Major Group: Rhodophyta - Class: Florideophyceae - Order: Ceramiales - Family: Rhodomelaceae