| Name | Macromitrium retusulum Müller Halle |
| Authorship | Müller Halle |
| Rank | Species |
| NomenclaturalStatus | NomLeg |
| Placed in | Macromitrium |
| Citation | 1879 Linnaea 42: 486 |
| Holdings | 4 Specimens held in the Harvard University Herbaria identified as Macromitrium retusulum Müller Halle |
| Identification made in | [no date] (2), 2013 (2) |