Preserving the integrity of types: what's a kleptotype?
A herbarium's most important specimens are its types. They must be handled very carefully, since these finite samples of fungal material are expected to last forever. When type specimens are loaned, herbaria trust that scientists will use discretion, using only a tiny amount for examination using a microscope. Sometimes mycologists speak of kleptotypes — mostly in a humorous way because this is not a formal term — referring to fragments of type specimens kept without permission of the lending herbarium.
Some have insinuated that E.J. Durand's herbarium includes many discomycete kleptotypes. The presence of so many types makes Durand's collection one of the best single places in the world to study the taxonomy of cup fungi. However, the idea that Durand purloined type fragments from other herbaria has been put to rest through a careful examination of his correspondence. He routinely asked for and was granted permission to keep type fragments by his sources.
Today, few herbaria would grant such permission. We ask that borrowers return every bit of the types, including microscope slides made from type specimens, and even GenBank numbers for DNA sequences derived from our specimens.