The University of Arizona Herbarium (ARIZ) is a research collection of over 425,000 dried plant specimens, with emphasis on the plants of the Sonoran Desert region and adjacent areas of the southwestern United States and northwestern Mexico.

Covid-19 update: The UA Herbarium remains closed except by appointment.
This summer (2021) we are happy to start slowly welcoming researchers and visitors on a limited basis, and by appointment only. We are available as always by email and (with some delay) by phone, and look forward to seeing and/or hearing from you.

herbarium @
520 621-7243

We wish the best for all, and hope everyone enjoys the monsoon flora (and fauna) of summer 2021.

Also -- we were honored to be visited by Arizona Illustrated! Check out the video at AZPM.



Search our collection of over 400,000 specimens.


Visit the Gilbertson Mycological Herbarium.


ARIZ works closely with a number of researchers in Arizona and around the country.


ARIZ is dedicated to identifying plants for members of the public, Arizona producers, Poison Control, anyone.

Featured projects


Weekly seminars are scheduled throughout the academic year.


Occasional workshops provide training in plant identification and more.

Section 6 Grants

Rare plant research: next deadline Oct 31, 2021

National Park Service

ARIZ and the National Park Service are partnering on a number of projects.

Legumes of Arizona

Legumes of Arizona: An Illustrated Flora and Reference will be a comprehensive account of the family Fabaceae in Arizona.

Flora of SW Arizona

ARIZ Associated Researchers are documenting modern and fossil plant diversity.


It is an ongoing effort to find funding to keep these projects alive, protect our specimens, and serve the public.


We are imaging our nearly 1500 type specimens.
For a complete listing of our projects, past and present, see our Projects page