The Society maintains a collection of books, reprints and periodicals housed within the library of the National Botanic Garden of Wales at Llanarthne near Carmarthen in Wales (see ). It contains about 6,000 items, including complete runs of the The Bulletin and The Lichenologist. Of special interest are two first editions of books by Acharius, the Swedish ‘father of lichenology’.

The library is open all weekdays, but changes made as a result of Covid-19 mean that the Archive Room where the BLS library is situated is now the permanent workplace of a member of NBGW staff. If you intend to visit the library please contact the BLS librarian Theresa Greenaway at least a week beforehand so that an appointment can be made.

Most, but not all, the books and periodicals can be borrowed by members in return for an undertaking to return the item plus reimbursing the National Botanic Garden of Wales for the postal costs.

Copies of reprints can be made by arrangement with the BLS librarian.