| Name | Mitthyridium constrictum (Sullivant) H. Robinson |
| Authorship | (Sullivant) H. Robinson |
| Rank | Species |
| NomenclaturalStatus | Unknown |
| Placed in | Mitthyridium |
| Holdings | 6 Specimens held in the Harvard University Herbaria identified as Mitthyridium constrictum (Sullivant) H. Robinson |
| Identification made in | 1978 (3), 2018 (3) |