Fronds are narrow, tough, and wiry, yet soft to the touch, and are dark brown to black when dry, measuring 2-3 mm wide and up to 250 mm long. They strongly resemble bottle-brush plants or laboratory glass-cleaning brushes due to the whorls of filaments arising from the main axis (as shown below, magnified). The branching is irregularly dichotomous. Plants missing the whorls may resemble Ahnfeltia plicata. The coralline alga Jania rubens is frequently found growing as an epiphyte at the base of the fronds.

Habitat: Found on rocks and stones, generally in areas affected by sand, in intertidal and shallow subtidal zones.