Description: Thallus small and filamentous, erect growing in tufts to 3 cms long. Downgrowing rhizoidal filaments do not form a cortex.

Habitat: Epilithic and epiphytic to depths of 14 m.

Distribution: Recorded from the British Isles from Dorset, Devon, Cornwall and the Shetlands. Europe: Portugal, Spain, France and the Netherlands.

Similar Species: All species of Aglaothamnion and Callithamnion are similar and not easy to identify.

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

iNaturalist: Aglaothamnion pseudobyssoides at iNaturalist World Species Observations database.

WoRMS: Aglaothamnion pseudobyssoides at World Register of Marine Species. Accepted name: Aglaothamnion pseudobyssoides (P.Crouan & H.Crouan) Halos, 1965. AphiaID: 144498.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Callithamniaceae; Callithamnioideae; Callithamnieae; Aglaothamnion