Description: Thallus filamentous, erect and finelhy branched in dense tufts to 5 cms long. Rhizoidal filaments grow down forming a cortex on the lower main axis.

Habitat: Uncommon. Epilithic and epiphytic in midlittoral and sublittoral to 10 m deep.

Distribution: Recorded from scattered sites around the British Isles including the Orkney Islands. Europe: Mediterranean and Portugal. Further afield: South Africa.

Similar Species: All species of Aglaothanmion and Callithamnion are similar and not easy to identify. Species of Compothamnion can be distinguished by the ecorticate main axis.

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

iNaturalist: Aglaothamnion tripinnatum at iNaturalist World Species Observations database.

WoRMS: Aglaothamnion tripinnatum at World Register of Marine Species. Accepted name: Aglaothamnion tripinnatum (C.Agardh) Feldmann-Mazoyer, 1941. AphiaID: 144502.

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