Description: Fine uniseriate filaments with few branches, erect to 30 mm, growing from well branched prostrate axes. Forms a compact smooth turf. Chloroplasts apparently without a pyrenoid.

Habitat: Found throughout the littoral zones generally on rock into the sublittoral where it is epiphytic on Laminaria stipes.

Distribution: Widespread around the British Isles and in the Northern Hemisphere. Europe: Mediterranean, Portugal, Atlantic coasts of Spain and France, Netherlands, Baltic Sea, Norway, Faroes and Iceland. Greenland. Atlantic coast of North America: Canada, Maine, New Hampshire, Massachusetts, Rhode Island and Connecticut. Further afield: Arctic Sea: Spitzbergen, Novaya Zemlya and Baffin Bay. Pacific coast of North America and Japan.

Similar Species: Rhodothamnionella floridula however has a pyrenoid in the chloroplasts.

Key Identification Features:

• Chloroplasts without a pyrenoid. Not so efficient a sand-binder as Rhodothamniella floridula.

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

iNaturalist: Rhodochorton purpureum at iNaturalist World Species Observations database.

WoRMS: Rhodochorton purpureum at World Register of Marine Species.