| Name | Calothrix contarenii (Zanardini) Bornet & Flahault |
| Authorship | (Zanardini) Bornet & Flahault |
| Rank | Species |
| Placed in | Calothrix C. Agardh ex Bornet & Flahault |
| Holdings | 2 Specimens held in the Harvard University Herbaria identified as Calothrix contarenii (Zanardini) Bornet & Flahault |
| Identification made in | [no date] (2) |