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 nearly 1500 type specimens. Many familiar Sonoran Desert plants were first named based on type specimens housed at ARIZ.

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 staff.

Collection information for all type specimens at ARIZ has been entered into our specimen database. Enhanced search capabilities for type specimens are planned for the future; for now, type status will appear on a record sought taxonomically and/or geographically.

Another way to explore our types is via JSTOR Global Plants. In collaboration with the herbarium at ASU, we recently completed a project that generated high-resolution images for all of our types. Low-resolution versions of ARIZ types are available from JSTOR here. Higher resolution images can be made available by contacting us and will be available through our website in the future.