| Name | Ulothrix flacca (Dillwyn) Thuret |
| Authorship | (Dillwyn) Thuret |
| Rank | Species |
| NomenclaturalStatus | NomLeg |
| Placed in | Ulothrix Kützing |
| Contains | Ulothrix flacca var. geniculata Y.Berger-Perrot Ulothrix flacca var. roscoffensis Y.Berger-Perrot |
| GUID | urn:lsid:marinespecies.org:taxname:145925 |
| Holdings | 28 Specimens held in the Harvard University Herbaria identified as Ulothrix flacca (Dillwyn) Thuret |
| Identification made in | [no date] (28) |