Ulothrix flacca
- kingdom: Plantae
- phylum: Chlorophyta
- class: Ulvophyceae
- order: Ulotrichales
- family: Ulotrichaceae
- genus: Ulothrix
- species: Ulothrix flacca
Nortorf
Schleswig-Holstein
Germany
Varberg
Halland
Sweden- United Kingdom
Akutan
Alaska
Bridgeport
Connecticut
Kittery
Kittery Point
Maine
Medford
Nahant
Somerville
Massachusetts
New Castle
New Hampshire
Glen Cove
Lattingtown
New York
United States
Caguas
Bembridge