Description: Thallus tubular, thread-like to 15 cms long, of 3 - 8 longitudinal rows of cells around a very narrow cavity, diameter the same throughout with only occasional branching. Majority of cells with more than one pyrenoid.

Habitat: Forming tangled masses in the littoral.

Distribution: Few records scattered around the British Isles. Europe: Portugal, Spain, France and the Netherlands.

Key Identification Features:

• Thallus tubular and more or less the same from base to apex.

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

iNaturalist: Enteromorpha ralfsii at iNaturalist World Species Observations database.

WoRMS: Enteromorpha ralfsii at World Register of Marine Species.