National Botanical Symposium

Barbara M. Thiers
New York Botanical Garden
U.S. herbaria: documenting 250 years of American botanical research

Lewis & Clark were charged with making herbarium specimens on their 1802 expedition, representing the first government funded effort to create a record of the nation’s vegetation. The failure of the government to safeguard the specimens from that expedition demonstrates the immaturity of U.S. scientific infrastructure at that time. Specimens collected on later 19th century government-sponsored expeditions were handled more efficiently, mostly by east coast botanists John Torrey and Asa Gray. New centers of botanical expertise emerged with westward settlement, reducing the dominance of east coast institutions in documenting the flora. Plant identification was part of the curriculum in U.S. institutions of higher learning, leading most to create their own herbaria. The advent of computer technology led to calls for herbaria to “computerize” their holdings to support a comprehensive flora of North America and emerging research programs in molecular biology and ecology in the late 1960s. Today approximately half the specimens held in U.S. herbaria have been digitized, and these data now support an increased range of research efforts. The herbarium community has always been cohesive and collaborative. We can build on this historical strength to promote a sense of global responsibility for protecting and continuing to grow our herbarium specimen heritage.

Biography
Barbara Thiers is Director Emerita and Curator at New York Botanical Garden, and Research Associate at the Denver Botanic Gardens. After completing her Ph.D. at the University of Massachusetts, she accepted a postdoctoral position at NYBG and stayed for 40 years. In addition to curation and a modest amount of floristic work on liverworts, she developed the NY specimen digitization program. In 2020 she published a book about herbaria geared to the general public, Herbarium: The Quest to Preserve and Classify the World's Plants. In retirement she is currently revising the liverworts of Colorado and creating a reference bryophyte collection at the Denver Botanic Gardens. She is past president of the American Society of Plant Taxonomists and the Society for the Preservation of Natural History. She is currently the Secretary of the Natural Science Collections Alliance and a member of the advisory board of the Biodiversity Collections Network. Thiers is also the Editor of Index Herbariorum.

Caroline A.E. Strömberg
University of Washington
The deep and tangled evolutionary roots of North American grasslands: insights from the fossil record

The deep-time history of North America’s grassland ecosystems is a crucial key to their present function and future responses to continued climate- and land use changes. Yet, until recently, relatively little was known about grassland assembly across North America during the Cenozoic (last 66 million years). The main reason for this knowledge gap was the spotty and ambiguous fossil record of grasses, leading researchers to rely on indirect evidence for vegetation change such as the evolution of large, herbivorous mammals reminiscent of today’s grazers. Novel approaches, including stable carbon isotopes, fossilized plant silica, and functional morphology of fossil grass fruits have shed new light on North America’s grassland evolution. These records, when compared to fossil faunas, point to a complex history of grasslands ecosystems. For example, the first open-habitat grasses, which appeared in Late Eocene subtropical forests, belonged to the largely cold-adapted Pooideae subfamily. By the Late Oligocene-Early Miocene, these grasses became abundant on the landscape, forming grassland-mosaics with palms, which hosted diverse mammal herbivore communities in climates that were warmer and wetter than today. These non-analog ecosystems hold clues to the factors that drove Cenozoic grassland assembly and shaped their ecological and evolutionary legacy.

Biography
Caroline Strömberg holds master’s and bachelor’s degrees in Historical Geology and Paleontology from Lund University in Sweden and a Ph.D. in Integrative Biology from the University of California, Berkeley (2003). She did postdoctoral work at the Swedish Museum of Natural History and the Smithsonian Institution’s National Museum of Natural History. Since 2008, she is the Estella B. Leopold Curator of Paleobotany at the Burke Museum of Natural History and Culture and Professor of Biology at the University of Washington, Seattle. The Strömberg Lab uses plant micro- and macrofossils to elucidate evolutionary and ecological links between plants and their environment through geologic time. Two enduring foci are the evolution of grasses/grassland ecosystems and biotic responses to Cenozoic climate change. However, the lab has also worked on vegetation change during the Cretaceous-Paleogene transition and the role of silica in plants, among other topics. 

Andrew Hipp
The Morton Arboretum
250 years of insights from America’s oaks

Oaks (Quercus, Fagaceae) are foundational species in a wide range of savannas and forests across the northern hemisphere. They have shaped scientists’ understanding of plant species, hybridization, and the evolution of northern forests. The oaks of the Americas have yielded particularly important insights in all of these areas. In this talk, I will present historical discoveries in the American oaks stretching back to the mid-18th century. In addition, I will present current research by my lab group and collaborators on the nature of oak species and the effects of oak biodiversity on the communities of organisms who depend on oaks. Building on the past two and a half centuries of American oak research will require strong collaborations. This work is essential to conserving oaks and managing their ecosystems for the future.

Biography
Andrew Hipp is Director of the Herbarium and Lead Scientist in Plant Systematics at The Morton Arboretum, and Lecturer in the Committee on Evolutionary Biology at University of Chicago. As director, Hipp has increased the herbarium’s research impacts locally and internationally and strengthened the herbarium as a community resource for students, researchers, and the public. Hipp and his lab group investigate the origins of plant biodiversity from populations to clades. Their current work with a team of collaborators focuses on how adaptation and hybridization shape oak diversity and the communities of organisms that depend on oaks. In addition to academic articles, Hipp has written a popular book on oaks—Oak Origins: From Acorns to Species and the Tree of Life—and numerous popular articles and natural history books for children. He is the current President of the American Society of Plant Taxonomists (ASPT) and serves on the scientific committee for the Global Botanic Gardens Congress 2027.

Rose Bear Don't Walk
Montana State University
First foods for health: how the traditional plant wisdom of the Bitterroot Salish influences history, wellbeing and cultural longevity

For thousands of years prior to colonization, the Bitterroot Salish or Séliš peoples lived in deep relation to the diverse landscape of what is now Northwest Montana. When Lewis and Clark wandered into their traditional territory of the Bitterroot Valley, the Séliš were well established in their Seasonal Round; a highly sophisticated cycle of understanding the environment and all living beings in it. One of the vital components of the Seasonal Round is traditional food plants. The first ethnobotanists of our time, the Salish (like many Indigenous peoples) have cultivated a deep intricate knowledge of flora through subsistence activities and reciprocity. As a result of colonization, this relationship has been adversely affected and with it, Salish health. Dr. Bear Don’t Walk will discuss the importance of Salish traditional food plants and how they have impacted and been impacted by history as well as their capacity for enhancing wellbeing. She will detail her research project First Foods for Health: A Community Exploration of Food Plants, Salish Health, and Our Futures conducted with her Salish community. Attendees will learn how cultural knowledge influences ethnobotany, why community-led research is vital to science, and how food plant restoration can restore a people.

Biography
Rose Bear Don't Walk seeks to bridge science, culture and health through her work with traditional indigenous foods and native plants of northwest Montana. A longtime resident of the Flathead Indian Reservation, Bear Don't Walk is a descendant of the Bitterroot Salish and Crow tribes of the state. She has a B.A. in Political Science from Yale University, an M.S. in Environmental Studies from the University of Montana, and will receive her Doctorate in Indigenous and Rural Health from Montana State University this May. As a Luce Indigenous Knowledge Fellow, she centers her work on the longstanding relationship Salish people have formed with local edible flora and its implications for community health and cultural longevity. Her research, First Foods for Health: A Community Exploration of Food Plants, Salish Health and our Futures recently completed with her community, serves as an ongoing relationship to restore, protect, and revitalize food plant knowledge. 

Wesley M. Knapp
Center for Plant Conservation
From discovery to conservation: how we can slow the sixth mass extinction

For 250 years, American botany has been defined by the discovery, naming, and documentation of plant life. Yet discovery has not ended. New plant species continue to be described each year, many of them narrowly endemic and immediately at risk of extinction. This reality reveals a central paradox of modern botany: we are still learning what exists, even as biodiversity is being lost at an unprecedented pace. As the United States marks its 250th anniversary, this moment invites reflection on what the next chapter of American botany must become. In this talk, I argue that the future of the discipline must be defined by conservation. Taxonomy provides the foundation for conservation, determining what species are recognized, assessed, and prioritized for action. Using Plants of One Known Occurrence (OKOs) as a focal example, I show that extreme rarity is far more common than is often appreciated and that species confined to a single occurrence are uniquely vulnerable to extinction. Traditional conservation approaches often fail to protect these taxa. I then describe how the Center for Plant Conservation transforms botanical knowledge into action through national coordination, data-driven prioritization, and integrated in situ and ex situ conservation. Together, these approaches offer one of our best opportunities to slow the sixth mass extinction and ensure that discovery leads not only to knowledge, but to lasting protection.

Biography
Wesley M. Knapp is a leading voice in plant conservation with more than two decades of experience advancing science-based strategies to prevent plant extinction. He holds a B.S. in Environmental Sciences from Catawba College, an M.S. in Plant Science from Delaware State University, and a Ph.D. in Ecology from the University of North Carolina at Chapel Hill. Knapp began his career with the Maryland Natural Heritage Program, where he served for 15 years as Eastern Region Ecologist and Botanist, followed by five years as Mountains Botanist and Ecologist for North Carolina’s Natural Heritage Program. In 2021, he became Chief Botanist at NatureServe, and in 2025 was appointed Chief Executive Officer of the Center for Plant Conservation, a nonprofit coordinating conservation action with more than 80 partner institutions across three continents. With extensive field experience in the United States and abroad, Knapp has helped describe new plant species, assess extinction risk, and build national conservation priorities. His work focuses on translating botanical knowledge into action to slow biodiversity loss during the sixth mass extinction.

Coming soon

2001    Linnaean Taxonomy in the 21st Century
2002    The Convention on Biological Diversity
2003    Botanical Frontiers in Southeast Asia
2004    Botanical Progress, Horticultural Innovations, and Cultural Changes
2005    The Future of Floras: New Frameworks, New Technologies, New Uses
2006    Island Archipelagos: Cauldrons of Evolution
2008    Partners in Evolution: Interactions, Adaptations, and Speciation
2009    Genes, Genomics and Genome Evolution in Plants
2010    Food for Thought: 21st Century Perspectives on Ethnobotany
2012    Transforming 21st Century Comparative Biology using Evolutionary Trees
2013    Avoiding Extinction: Contemporary Approaches to Conservation Science
2014    Location, Location, Location...New Advances in the Science of Biogeography
2015    Next Generation Pteridology: An International Conference on Lycophyte & Fern Research
2016    Bats, Bees, Birds, Butterflies and Bouquets: New Research in Pollination Biology
2017    Exploring the Natural World: Plants, People and Places
2018    Plants in the Past: Fossils and the Future
2019    What Darwin Couldn't Know: Modern Perspectives on Crop Plant Origins
2021    Plant Symbiosis: The Good, the Bad, and the Complicated
2022    Life on the Edge: Exceptional Plants in Exceptional Place
2023    New Horizons in the Study of Neotropical Floras
2024    Advancing Plant Conservation Through Horticulture
2025    The Future of Collections-Based Plant Science