Description: The largest of our algae. The thallus grows to 5 m long with a flat frond, tough, smooth and rubbery, without a midrib and digitate. Holdfast at first discoid later enveloped by a large warty structure which eventually envelopes it. Stipe compressed with a spiral twist above the swollen base it grows to 1 m or more in length with a strongly waved border

Habitat: Locally common. Low littoral to 30 m in the sublittoral. Usually epilithic.

Distribution: Generally western distribution in the British Isles. Europe: generally only west Mediterranean but has been reported from Italy, Portugal, Atlantic coasts of Spain and France and Norway but not within the Arctic Circle. Further afield: Canary Islands, west coast of Africa, Morocco, Mauritania, Ghana and west Africa.

Similar Species: Laminaria digitata, Laminaria hyperborea and Laminaria saccharina do not have a flattened stipe. Alaria esculenta has a midrib.

Key Identification Features:

• Large sizs, digitate frond, stipe with wavy margins.

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

iNaturalist: Saccorhiza polyschides at iNaturalist World Species Observations database.

WoRMS: Saccorhiza polyschides at World Register of Marine Species. Accepted name: Saccorhiza polyschides (Lightfoot) Batters, 1902. AphiaID: 145735.

Classification: Biota; Chromista; Harosa; Heterokonta; Ochrophyta; Phaeophyceae; Fucophycidae; Tilopteridales; Phyllariaceae; Saccorhiza