Description: Thallis with prostrate axes spreading over the substrate and giving rise to erect filamentous tufts rising to 20 cms. Branching irregular.

Habitat: Epilithic and epiphytic, from extreme low littoral to 10 m depth.

Distribution: Very rare, recorded at only a few sites in the south-west of the British Isles

Similar Species: Spermothamnion spp.

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

iNaturalist: Ptilothamnion sphaericum at iNaturalist World Species Observations database.

GBIF data for Ptilothamnion sphaericum

WoRMS: Ptilothamnion sphaericum at World Register of Marine Species. Accepted name: Ptilothamnion sphaericum (P.L.Crouan & H.M.Crouan ex J.Agardh) Maggs & Hommersand, 1993. AphiaID: 144690.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Wrangeliaceae; Lejolisieae; Ptilothamnion