| Name | Parmelia diffusa (Weber) Rebentisch |
| Authorship | (Weber) Rebentisch |
| Rank | Species |
| Placed in | Parmelia Acharius |
| Citation | 1804 Prodr. Fl. Neomarch. 301 |
| Holdings | 2 Specimens held in the Harvard University Herbaria identified as Parmelia diffusa (Weber) Rebentisch |
| Identification made in | [no date] (2) |