Among the collections of the Hong Kong Herbarium, there are about 300 type specimens, making the Herbarium regionally important.
What is a type specimen?
A type specimen is a herbarium specimen which was described and used for the designation of the scientific name of a new species, in accordance with the requirements set out in the International Code of Nomenclature for algae, fungi and plants (ICN). Under the rule of the Code, the name and its type specimen are permanently linked. The type specimen is usually cited in the scientific publication that describes the new species. Information of the specimen such as the field number, herbarium number, location of collection and the herbarium where it has been deposited is usually given in the publication.
Importance of a type specimen
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Type specimen is unique and there can only be a single type specimen (generally holotype) for each nomenclatural element in the whole world.
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Type specimen is among the most valuable asset in any herbarium. In the event of a discrepancy between various descriptions of an element or identification of unknown plant specimens, the type specimen will always be the definitive reference and material to clarify the matter.
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Type specimens are the essential materials for conducting taxonomic review.
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Type specimens are permanent records deposited usually in public herbaria for open access by bona fide botanists. The ICN strongly recommended that the material on which the name of a taxon is based, especially the holotype, is deposited in a public herbarium or other public collection with a policy of giving bona fide botanists open access to deposited material, and is scrupulously conserved.
Different types of type specimens
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A holotype is the single specimen used by the author, or designated by the author as the type specimen of the name of a species (or subspecies or variety).
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A lectotype is a specimen chosen by a subsequent author to serve as the definitive type.
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An isotype is any duplicate of the holotype.