Description: Erect thalli less than 3 mm wide growing from a fibrous holdfast to 20 cms long. Firm and cartilaginous, branching dense, flattened and irregular with midrib. In summer with a tuft of filaments at the ends of the branches.

Habitat: Occasional. Epilithic in the sublittoral to more tham 30 m depth.

Distribution: Western distribution in the British Isles: Ireland, Scotland and the south-west coasts of Wales and England, Isle of Man and the Channel Islands. Europe: Mediterranean, Azores, Portugal, Spain and France. Further afield: the Canary Islands, South Africa, Australia, New Zealand and Japan.

Similar Species: The only other species with terminal tufts is Sporochnus pedunculatus which has terete thalli.

Key Identification Features:

• In summer with terminal tuft of filaments 4 - 6 mm long.

Distribution Map from NBN: Carpomitra costata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Carpomitra costata at iNaturalist World Species Observations database.

WoRMS: Carpomitra costata at World Register of Marine Species. Accepted name: Carpomitra costata (Stackhouse) Batters, 1902. AphiaID: 145910.

Classification: Biota; Chromista; Harosa; Heterokonta; Ochrophyta; Phaeophyceae; Fucophycidae; Sporochnales; Sporochnaceae; Carpomitra