Polysiphonia exilis
- kingdom: Plantae
- phylum: Rhodophyta
- class: Florideophyceae
- order: Ceramiales
- family: Rhodomelaceae
- genus: Polysiphonia
- species: Polysiphonia exilis
Duncan Town
Ragged Island
Bahamas
Ifalik
Yap
Micronesia, Federated States Of
Jobos
Guayama
Puerto Rico
Key West
Florida- Mā‘ili
- Princeville
- Wai‘anae
Hawaii
United States