Description: Thallus fan-shaped and flat, arising from a small discoid holdfast to 6 cms long, braching dichotomously, each branch 2 or 3 mm wide.

Habitat: Epiphytic on Laminaria in the sublittoral to at least 30 m deep on sheltered and exposed shores.

Distribution: Of northern distribution in the British Isles: England, Wales and Scotland including the Shetlands. Europe: Denmark, the Baltic, Norway, Faroes, Spitzbergen and Iceland. Greenland. Atlantic coast North America: Canada, Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, Long Island and New Jersey. Further afield: Arctic Sea including Novaya Zemlya and Baffin Bay, apparently circumpolar and north Pacific (as Euthora fruticulosa (Rupr.) J.Ag.

Similar Species: Sphaerococcus coronopifolius and Plocamium cartilagineum

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

iNaturalist: Callophyllis cristata at iNaturalist World Species Observations database.

WoRMS: Callophyllis cristata at World Register of Marine Species. Accepted name: Euthora cristata (C.Agardh) J.Agardh, 1847. AphiaID: 373772.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Gigartinales; Kallymeniaceae; Callophyllis