Aglaothamnion tenuissimum
- kingdom: Plantae
- phylum: Rhodophyta
- class: Florideophyceae
- order: Ceramiales
- family: Callithamniaceae
- genus: Aglaothamnion
- species: Aglaothamnion tenuissimum
Welchman Hall
Saint Thomas
Barbados
Yerseke
Zeeland
Netherlands
Tallaboa
Penuelas
Central Aguirre
Salinas
Puerto Rico
Hugh Town
Isles of Scilly
Lymington
Rayne
England
United Kingdom
Oak Bluffs
Massachusetts
United States