Description: Only the tetrasporic plants are known. Growing as small dark red crust up to 10 mm in diameter. Gives rise to erect filaments about 20 cells long united by mucilage.

Habitat: Very rare. Epilithic in the sublittoral to 15 m.

Distribution: Scattered records around the British Isles. Europe: west Baltic, Helgoland and Norway. Atlantic coast of North America from Canada and Maine.

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

iNaturalist: Plagiospora gracilis at iNaturalist World Species Observations database.

WoRMS: Plagiospora gracilis at World Register of Marine Species. Accepted name: Plagiospora gracilis Kuckuck, 1897. AphiaID: 145233.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Gigartinales; Gloiosiphoniaceae; Plagiospora