| Name | Marasmius opacus Berkeley & M. A. Curtis |
| Authorship | Berkeley & M. A. Curtis |
| Rank | Species |
| Placed in | Marasmius |
| Citation | 1849 Hooker's J. Bot. Kew Gard. Misc. 1: 99 |
| Holdings | 6 Specimens held in the Harvard University Herbaria identified as Marasmius opacus Berkeley & M. A. Curtis |
| Identification made in | [no date] (6) |