Description: Tufts of fine erect filaments, unbranched and densely packed shoots arising from a discoid base up to 30 mm long, at first uniseriate later mare than one cell wide the inner cells large and colourless.

Habitat: Not uncommon. Epiphytic, on Laminaria and other species. In lower littoral rock pools and shallow sublittoral.

Distribution: Widely distributed around the British Isles. Europe: Netherlands, Germany, Denmark, Baltic, Sweden, Norway, Faroes and Iceland. Greenland. Atlantic coast of North America: Canada, Maine and Rhode Island.

Similar Species: Many fine filamentous brown algae are similar, microscopic examination is required for identification.

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

iNaturalist: Pogotrichum filiforme at iNaturalist World Species Observations database.

WoRMS: Pogotrichum filiforme at World Register of Marine Species. Accepted name: Pogotrichum filiforme Reinke, 1892. AphiaID: 238952.

Classification: Biota; Chromista; Harosa; Heterokonta; Ochrophyta; Phaeophyceae; Fucophycidae; Ectocarpales; Acinetosporaceae; Pogotrichum