Celebrating the Legacy of the Ada Hayden Herbarium
The Ada Hayden Herbarium at Iowa State University is one of the nation’s most significant botanical collections, preserving more than 700,000 specimens of plants, fungi, and lichens from Iowa and beyond. Named for Dr. Ada Hayden—the first woman to earn a Ph.D. from Iowa State—the herbarium reflects her lasting impact on botanical research, prairie conservation, and scientific leadership.
In recognition of Women’s History Month, we spoke with curator Alexa DiNicola, director Lynn Clark, and former curator Deb Lewis about the herbarium’s history, its continued value for research and education, and its future as a resource for biodiversity science and conservation.
Q: What makes Ada Hayden’s legacy so central to the identity of the herbarium?
Dr. Hayden was a leader, a botanical polymath, a real force of nature, and a real force for nature. During her twenty-plus years at the Iowa State herbarium, she personally added over 15,000 high-quality specimens, making her among the most prolific single collectors we've had; her specimens alone still represent over 2% of our collection, which is saying something given how much we’ve grown since. She was an insightful botanist who did excellent floristic work and published in fields as diverse as plant anatomy and bird nesting ecology. Her botanical illustrations include not only precise, beautiful pen-and-ink technical work but also hand-painted lantern slides and other works of art. As the first woman to earn a Ph.D. from Iowa State—and only the fourth person to do so—she pushed through considerable social pressure against women in science, and she did it with no-nonsense brusqueness that earned her nicknames like "the worthy Ada".
Perhaps most importantly, though, she was a determined and fearless leader both in science and in conservation policy. She fell in love with the prairie as a child on her family's farm and became both one of the first scientists to study it and one of the first Euro-American advocates for its conservation—certainly the first for conserving Iowa's prairies. Her outspoken leadership and thorough documentation are the reason we have the Iowa State Preserve system; in turn, those preserves now protect a very substantial percentage of Iowa's last unplowed prairies. She advocated for prairie restoration and saw it implemented, so that the unplowed prairies wouldn’t be the only ones left.
Yet, for all that, she was granted little recognition during her lifetime. She was never allowed to advance beyond assistant professor. Other major contributors to the herbarium—Charles Bessey, say, or Louis Pammel—have already been honored on ISU’s campus. How better to memorialize Dr. Hayden than with the name of the museum to which she gave so much?
Q: How do historical specimens continue to advance scientific research today?
The oldest known herbarium specimens, which are in Europe, are over 500 years old. The oldest specimens in the Ada Hayden Herbarium are about 200 years old, with the majority collected within the last hundred years and new ones always being added. With proper preservation and handling, the oldest specimens can be as informative as the newest ones. Specimens continue to be used, as always, for documenting and understanding species diversity and characteristics in different groups (taxonomy) or in different areas (floristics). Herbarium specimens serve as a reference collection for confirming the identification of already named plants or identifying/describing species new to science. They provide material for studies of pollen and spores, microscopic structures, archeological samples, chemical analysis, forensics, plant diseases and plant/pest interactions, and illustration, among other uses. With new technology we can extract DNA from small amounts of dried tissue, even from older specimens, unlocking a wealth of data to answer questions about populations, species, and bigger branches in the tree of life. Imaging and databasing of specimens contribute to the Big Data revolution, which allows analysis of big patterns like the effects of climate change on flowering time, the distribution of species, etc. Natural history collections, including herbaria, remain a critical tool in the study and conservation of biodiversity.
Q: What is the herbarium doing today to expand accessibility and scientific impact?
Digitization involves taking high-resolution photos of specimens, then transcribing their labels into a database alongside those photos. When we make that data available online through portals like the Consortium of Northern Great Plains Herbaria (ngpherbaria.org), anyone can access our data from anywhere—it's an enormous accessibility upgrade. It also dramatically improves usability of the physical collection: with a relational database, we’ll be able to answer questions in two lines of code that would otherwise take weeks of person-hours. The collection is currently about 8% digitized, and we are seeking funding to continue the process.
We also have an outreach program that includes herbarium tours, botany walks, presentations to community groups and university classes, and more. Undergraduate students conduct research projects here, too, with our guidance. Even just advertising ourselves helps improve accessibility—no one uses a resource that they don’t know exists! We are open to the public: just contact the curator, dinicola@iastate.edu
Q: How has the herbarium grown over time, and what does that growth mean for Iowa plant research?
When the herbarium was founded in 1870, we had just a few thousand specimens. Since then, we've grown to about 730,000 specimens of plants, lichens, and fungi. About 525,000 of those were first accessioned here. The rest came from the herbaria of the University of Iowa and the University of Northern Iowa: when those colleges decided to close their herbaria in the 1990s and 2000s, we offered to take in their collections. We're now the last large herbarium, and by far the largest herbarium, in the state.
Our sheer size lets us support research across many botanical and related fields. Research on the Iowa flora, ecology, etc. can benefit from our especially extensive Iowa collections, where many samples of the same species capture its range of variation, its change over time, and its habitat’s changes. Research on particular taxa can benefit from collections originating in Iowa, North America, and around the world—we have specimens from all seven continents—which provide global cross-sections of biodiversity. Historical research can benefit from specialized sets like the C.C. Parry collection, 15,000 specimens that include the first European collections from much of the western US, or the fungi collected by A.P. Morgan and further documented in Laura Morgan's watercolors.
We're still always growing, too. Every day we add specimens collected by the scientists who work here or exchanged with us from other herbaria worldwide. We’ve just recently accessioned, among others, a few dozen mosses from Japan; 30-odd specimens documenting unusual plant distributions across Iowa; several dozen vouchers for the flora of an Iowa prairie preserve; and type specimens—each of which is part of the very definition of its species—including a spiderwort, a tiny mustard, and several bamboos. These specimens came to us through research activities, and they in turn will support future research and teaching.
Q: What excites you most about the herbarium’s future?
There are so many possibilities! Continuing and even completing digitization is a big one, both for accessibility and for usability. Once we've done at least some of that, we'll work on cross-referencing our database with the living collections, DNA resources, historical notes, etc. related to each specimen. As noted above, digitization offers all kinds of big data possibilities, and extending our database can only improve them. From there, we could work on larger floristic projects, perhaps a public-facing site like minnesotawildflowers.org.
I also can’t wait to see what ideas and projects our students will bring up. Those are much harder to predict, though, since I can’t exactly plan for someone else’s brilliant idea—only make sure that we’re ready to support them and cheer them on. Similarly, we will support future conservation work in Iowa and beyond.
Above all, though, I’m thrilled to be watching the proverbial pendulum start swinging back. Since the molecular biology revolution, classical resources like herbaria have fallen out of favor (regardless of how useful they still are); as the biodiversity and climate crises become impossible to ignore, though, we've begun seeing more grassroots interest in biodiversity science. Watching people respond to those crises with genuine interest and care is a truly hopeful experience.
Want to learn more?
Contact the curator, Alexa DiNicola: dinicola@iastate.edu or 515-294-9499