How to … Cite a specimen
Citing specimens in taxonomic publications, including protologues, is an important way to connect a taxonomic concept to the physical specimens on which that concept is based.
Most importantly, a specimen needs to be cited when it is designated or indicated as the type of the name of a species or infraspecific taxon.
Best practice when citing a specimen is to cite the collector and collector's number (if one exists), the date of collection, the herbarium where the specimen is deposited (see How to cite a herbarium), and the unique catalogue number, accession number, or barcode for the specimen in the herbarium.
Note that different journals have different styles for formatting these elements and for citing specimens. Always check the journal's Instructions for Authors as well as recent papers in the journal.