A bright red or pink seaweed. Each plant has a small disk-shaped base and erect fronds. The fronds consist of short cylindrical stipes (stalks) rarely longer than 1cm long and blades which may be up to 15 cm long and 10 mm wide. The fronds are dichotomously branched, with undulating margins and an indistinct midrib. The tip of each frond is distinctly rounded. The fronds are perennial and in some case 5 or 6 new periods of growth can be identified. Regeneration occurs following erosion or animal grazing. Continual regeneration leads to great variation in the appearance of individual plants as each new growth could come from the end, margin or surface of the blade. Fronds are frequently encrusted with the spiral tube worm Spirorbis spirorbis
or bryozoans.Phyllophora crispa
is a cartilaginous seaweed and can, therefore, hold its shape out of water.