Antithamnionella floccosa
- kingdom: Plantae
- phylum: Rhodophyta
- class: Florideophyceae
- order: Ceramiales
- family: Ceramiaceae
- genus: Antithamnionella
- species: Antithamnionella floccosa
North Saanich
British Columbia
CanadaIsle of Cumbrae
Millport
Peterhead
Wick
Scotland
United KingdomCarmel-by-the-Sea
La Jolla
Santa Cruz
CaliforniaPortland
South Portland
MaineGloucester
Lynn
Swampscott
MassachusettsFriday Harbor
Washington
United States