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.

In recognition of the COVID-19 pandemic, the UA Herbarium will be closed March 16 through the pandemic.

We remain available by email or phone:
(520) 621-7243
herbarium at

We hope you can get out doors to enjoy our beautiful landscape, and wonder about its fabulous flora. We remain ready to help! Please stay safe everyone, we'll see you on the other side.



Search our collection of over 400,000 specimens.


Search our literature collection.


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: deadline Jan 29, 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