| Name | Collema subnigrescens f. caesium (Clemente) Degelius |
| Authorship | (Clemente) Degelius |
| Rank | Forma |
| NomenclaturalStatus | NomLeg |
| Placed in | Collema subnigrescens Degelius |
| GUID | urn:lsid:indexfungorum.org:names:481400 |
| Citation | 1954 Symb. Bot. Upsal. 13(no. 2): 417 |
| Holdings | 1 Specimen held in the Harvard University Herbaria identified as Collema subnigrescens f. caesium (Clemente) Degelius |
| Identification made in | 2002 (1) |