The Lichen Herbarium contains ca 100 000 specimens.
Most of these are from Norway, but there are also large and important collections from North America by T. Tønsberg and from Bouvet Island and Antarctica by T. Engelskjøn. Important collectors are J.J. Havaas, J.M. Norman and T. Tønsberg. The entire Lichen Herbarium has been databased. Information about literature on lichens can be found here:
Recent Literature on Lichens. (https://nhm2.uio.no/botanisk/lav/RLL/RLL.HTM)
Search the collection (https://samlingsportal.nhm.uio.no/museum/um)