| Name | Calyptridium pygmaeum Parish ex Rydberg |
| Authorship | Parish ex Rydberg |
| Rank | Species |
| NomenclaturalStatus | NomLeg |
| Placed in | Calyptridium Nuttall |
| GUID | urn:lsid:ipni.org:names:273944-2 |
| Citation | 1932 N. Amer. Fl. 21: 320 |
| Holdings | 5 Specimens held in the Harvard University Herbaria identified as Calyptridium pygmaeum Parish ex Rydberg |
| Identification made in | [no date] (3), 1945 (1), 2008 (1) |