Description: Fine prostrate unbranched entangled filaments up to 15 cms long, rigid to the touch.

Habitat: Abundant. On mud, sand and rock in the upper littoral.

Distribution: Widely distributed in the British Isles from the Shetlands to Lundy. Europe: Mediterranean, France, Netherlands, Baltic Sea. Atlantic coast of North America: New York, North Carolina. Further afield: west coast of Greenland in Baffin Bay, the Canary Islands, Bermuda and the Pacific from California.

Similar Species: Rhiozoclonium riparium.

Key Identification Features:

• The genus can be distinguished by the presence of rhizoidal branchlets.

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

iNaturalist: Rhizoclonium tortuosum at iNaturalist World Species Observations database.

WoRMS: Rhizoclonium tortuosum at World Register of Marine Species. Accepted name: Rhizoclonium tortuosum (Dillwyn) Kützing, 1845. AphiaID: 145076.

Classification: Biota; Plantae; Viridiplantae; Chlorophyta; Chlorophytina; Ulvophyceae; Cladophorales; Cladophoraceae; Rhizoclonium