Description: Thallus uniseriate in erect dense tufts to 15 cms long. Rhizoidal filaments form a thick cortex.

Habitat: Epiphytic, epilithic and epizoic in the lower littoral.

Distribution: Widely distributed in the British Isles. Further afield: Canary Islands.

Similar Species: All species of Callithamnion and Aglaothamnion are similiar.

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

iNaturalist: Callithamnion granulatum at iNaturalist World Species Observations database.

WoRMS: Callithamnion granulatum at World Register of Marine Species. Accepted name: Callithamnion granulatum (Ducluzeau) C.Agardh, 1828. AphiaID: 144528.

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