Description: Thalli large, main axes erect and cylindrical, branches completely corticate to 20 cm long with small corticating cells at the nodes and long ones between. Ramuli monosiphonous, irregularly spirally arranged to 1.5 mm long.

Habitat: Epilithic and epiphytic mainly sublittoral to 13 m.

Distribution: British Isles: south and west coasts of Britain and Ireland, including the Channel Islands. Europe: Mediterranean, Portugal, Atlantic coasts of Spain and France. Atlantic coast of North America: Canada, Massachusetts, Rhode Island, Connecticut and Long Island, New Jersey, Delaware, Maryland and Virginia and Florida. Further afield: Canary Islands, Bermuda, Bahamas, West Indies, Red Sea, South Africa, Mauritius, Indian Ocean, Australia, Tasmania and California. Widely distributed in the subtropics and subtropics.

Key Identification Features:

• Main axes and branches corticate, ecorticate ramuli.

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

iNaturalist: Spyridia filamentosa at iNaturalist World Species Observations database.

WoRMS: Spyridia filamentosa at World Register of Marine Species. Accepted name: Spyridia filamentosa (Wulfen) Harvey, 1833. AphiaID: 144706.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Callithamniaceae; Spyridioideae; Spyridieae; Spyridia