Description: Thallus tubular bounded by a membrane one cell thick, the upper part compressed, to 30 cms or more long and branched the branches being up to 2 cms wide. Cells in surface view in no definite order. Chloroplasts usually hood-shaped with one pyrenoid.

Habitat: Common. Epilithic and epiphytic in the littoral, also in brackish water.

Distribution: Widespread in the British Isles. General world-wide distribution.

Similar Species: Other species of Enteromorpha especially E.intestinalis which is unbranched. Microscopic examination required for confirmation.

Key Identification Features:

• Tubular but compressed appearing as two cells thick, branched.

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

iNaturalist: Enteromorpha compressa at iNaturalist World Species Observations database.

WoRMS: Enteromorpha compressa at World Register of Marine Species. Accepted name: Ulva compressa Linnaeus, 1753. AphiaID: 234462.

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