What is a "type"?

"Types" are specimens upon which scientific names are based. Under the laws of Botanical Nomenclature, a botanist who describes a new species must designate a type specimen deposited at a particular herbarium. Type specimens are extremely important for verifying scientific names.

Type Specimens at ARIZ

One of the most important assets of the University of Arizona Herbarium is our collection of more than 1300 type specimens. Many familiar Sonoran Desert plants were first named based on type specimens housed at the University of Arizona Herbarium.

Access to type specimens

Because of their great scientific importance and irreplaceable nature, type specimens are housed separately from the rest of the collection. They can be consulted only by special permission from Herbarium curators.

Collection information for all type specimens at ARIZ has been entered into our specimen database. You may search for ARIZ types using our Specimen Search Engine. To do so click in the box next to "Types only" and then type the taxon name for which you want browse the types for in the "Taxon" box. We have also begun scanning our type specimens and plan to make these high-resolution images available via this website in the near future.