Phyllophora crispa is a medium-sized fleshy, marine red alga.

This alga forms dense mats of up to 15 cm thickness, which influence environmental factors, thus creating habitat for several associated organisms.

The frond is firm bright red in colour and with flattened parallel sides.

[2] Epilithic, found deep rock pools in the lower littoral[5] and to a depth of 30 m in the sublittoral.

[3] Generally common around Ireland, Great Britain as far north as Shetland and the Isle of Man.