Ada Hayden Herbarium
About Us
The Ada Hayden Herbarium has the largest collection of Iowa plants and fungi, containing over 710,000 specimens of vascular plants, bryophytes, fungi, and lichens. Functioning primarily as a research facility important for taxonomic studies (occurrence, distribution, and relationships of plants), it is also used for identifying unknown plants and to support numerous other types of research.
Specimens are loaned to specialists at other institutions around the world to support research. Loans from other institutions allow our researchers access to other herbaria. Recently, herbaria have become a source of materials to use in molecular studies and to support basic research on biodiversity.
Digitization of our specimens (imaging and databasing to make them partly accessible online) is an ongoing process, less than 10% complete as of August 2025. The available vascular plant specimens are accessible via the Consortium of Great Plains Herbaria, linked above.
For links to search our nonvascular plants, lichens, and fungi, see Specimen Digitization.
Questions?
Contact the curator, Alexa DiNicola: dinicola@iastate.edu or 515-294-9499.
Ada Hayden Herbarium's 150th Anniversary in 2020
Information and videos are available on the Celebrating the Ada Hayden Herbarium's 150th Anniversary page.
Ada Hayden
Curator, Iowa State Herbarium, 1934-1950
Ada Hayden was a leader in science, a fearless advocate for the prairie, and an exceptional herbarium curator. The first woman to receive a doctorate at Iowa State College (now called Iowa State University), she was born in 1884 in rural Ames. Dr. Louis Pammel, a professor at Iowa State College, encouraged her since secondary school to study botany at the college. After receiving her bachelor's degree in from Iowa State 1908 and her master's degree in botany in 1910 from Washington University in St. Louis, she returned to Iowa State as both a botany instructor and a graduate student in 1911. She earned her doctorate in 1918, making her the fourth student, male or female, to obtain a Ph.D. at Iowa State College.