The terms herbarium specimen, voucher specimen, and type specimen refer to botanical specimens with a particular use or quality.
Herbarium specimen The term
herbarium specimen emphasizes the fact that a botanical specimen has been deposited in a herbarium, an institution specifically designed to facilitate the sharing of preserved specimens. A herbarium specimen is usually dried, pressed, and mounted on paper but other methods of preservation are used as well. A
voucher specimen is a herbarium specimen intended to support a research project or a field survey. Among other things, vouchers help to protect against errors in plant identification.
Type specimen in 1841 To be useful, a botanical specimen must be identified as a member of some
taxonomic group at a given
rank. Whether or not the collector identifies the specimen initially, other botanists are free to make a
determination at any time. If a botanist believes that the specimen represents a new
taxon, the botanist may publish a new name and description, in which case she becomes the author of the name and the specimen becomes the
type of the taxon. Every plant
species is associated with a type, either a botanical specimen or a
botanical illustration. In either case the type serves as the basis for the
botanical name of the taxon. In 1841, the American botanist
Ferdinand Rugel collected two specimens, one in
North Carolina and the other in
Georgia. The English botanist
Alfred Barton Rendle published new names and descriptions for both specimens in 1901. Rendle applied the names
Trillium rugelii and
Trillium affine, respectively. In the 1980s, the American botanist
Thomas Stewart Patrick determined that both specimens represented a single species. In the previous scenario, Rugel is the collector, Rendle is the author, and Patrick is the determiner. Obviously Rendle and Patrick disagree but anyone can inspect the specimens, read the descriptions, and formulate an opinion: either there are two distinct species,
Trillium rugelii and
Trillium affine , or the name
Trillium affine is a
synonym for
Trillium rugelii . , botanists favor a single species concept. Future opinion might change but in any case,
Trillium affine is still a validly named and described species, and its type is the specimen collected by Rugel in Georgia in 1841. ==Famous collectors==