Description: Thallus unbranched to 30 cms long and 5 cms wide with distinct stipe. The two side membranes almost wholly adpressed with only a hollow stipe and free at the margins. Cells arranged in longitudinal and transverse rows.

Habitat: Common. Epilithic in rock pools in the littoral and sublittoral.

Distribution: Widely distributed around the British Isles. Europe: Mediterranean, Azores, Portugal, Atlantic coasts of Spain and France, Netherlands, Baltic Sea, Norway, Faroes and Russia. Atlantic coast of North America: Canada, Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New Jersey, Delaware, Maryland, Virginia and South Carolina. Further afield: Canary Islands, Caribbean, Bermuda, Alaska to California, Mexico, Chile, South Africa and Japan.

Similar Species: Ulva lactuca is flat, broad and firmer, two cells thick the two layers being quite inseparable. Microscopic examination may be required for confirmation.

Key Identification Features:

• Unbranched with cells arranged in rows.

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

iNaturalist: Ulva linza at iNaturalist World Species Observations database.

GBIF data for Ulva linza

WoRMS: Ulva linza at World Register of Marine Species. Accepted name: Ulva linza Linnaeus, 1753. AphiaID: 234474.

Classification: Biota; Plantae; Viridiplantae; Chlorophyta; Chlorophytina; Ulvophyceae; Ulvales; Ulvaceae; Ulva