Description: An erect terete frond about 2 mm in diameter and up to 20 cms long rising from a branched holdfast. Numerous primary branches at irregular intervals and secondary branchlets, becoming bushy. The branchlets taper slightly at their base and at the apex.

Habitat: Common. Epilithic in pools in the midlittoral into the sublittoral to a depth of 24 m with a broad range of habitats.

Distribution: Widespread around the British Isles including the Shetlands, Isle of Man and the Channel Islands. Europe: Spain, France, Netherlands, the Baltic, Faroes, Norway and Iceland. Greenland. Atlantic coast of North America: Canada, Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut and New Jersey. Further afield: Arctic Sea from the Novaya Zemlya and Baffin Bay.

Similar Species: Gracilaria gracilis and some species of Polysiphonia. Generally distinguished not being polysiphonous and with branches which are narrow where they branch from the main axis.

Key Identification Features:

• Not polysiphonous with branches constricting at their base. Branched holdfast.

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

iNaturalist: Cystoclonium purpureum at iNaturalist World Species Observations database.

WoRMS: Cystoclonium purpureum at World Register of Marine Species. Accepted name: Cystoclonium purpureum (Hudson) Batters, 1902. AphiaID: 145615.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Gigartinales; Cystocloniaceae; Cystoclonium