In botany, herbariums constitute the material support that is indispensable for any scientific study. However, the contents of numerous collections often remain unknown, to the detriment of knowledge and of the conservation of the natural patrimony. This article proposes an inventory of the herbariums of lichens in the natural history museum of Aix-en-Provence and of the works in which they were studied in order to extract the scientific and historic data they contain. These collections, with a total of about 30 000 samples, include: (1) a general herbarium of 11 000 samples constituted on the basis of contributions from eminent 19th and 20th century lichenologists; (2) the regional herbariums of the southeast of France established by G. Couderc, R. Dughi and L. Berner; and (3) diverse small herbariums from France and overseas. Completed and stored by R. Dughi and P. Ducos, they have given rise to about thirty articles in the fields of floristic, taxonomy and biology. The Aix-en-Provence natural history museum can thus constitute a source of extensive and high quality material for future scientific research, now that its existence is finally known. More generally, it would appear worthwhile to list all herbariums and to inventory their content.