| Name | Rhizocarpon reductum Th. Fries |
| Authorship | Th. Fries |
| Rank | Species |
| Placed in | Rhizocarpon Ramond ex de Candolle |
| GUID | urn:lsid:indexfungorum.org:names:404076 |
| Citation | 1874 Lichenogr. Scand. 1: 633 |
| Holdings | 27 Specimens held in the Harvard University Herbaria identified as Rhizocarpon reductum Th. Fries |
| Identification made in | [no date] (19), 1995 (1), 1998 (2), 2001 (2), 2013 (1), 2016 (1), 2019 (1) |