The Lois Porter Earle Herbarium
What Is the Herbarium?
A herbarium is a library of pressed, dried plant specimens, each one a permanent, dated and mapped record of a plant at a specific place and time. The Lois Porter Earle Herbarium is the largest in Arizona supported by a nonprofit institution and the fourth largest in the state overall, with particular strength in Arizona flora, cacti and agaves.
Nearly every specimen is databased and georeferenced, and specimen records are freely searchable online through the Southwest Environmental Information Network (SEINet), making the collection a working resource for researchers, land managers and other institutions, not just an archive.
A History of Discovery
1939
Desert Botanical Garden is founded and early plant collecting begins informally.
1970
Dedicated herbarium space, storage cabinets and staffing are established, allowing the collection to grow in earnest from roughly 25,000 specimens.
1972
The Herbarium is designated a National Resource Collection.
1983
The Garden earns accreditation from the American Alliance of Museums.
1985
The Garden becomes a charter member of the Center for Plant Conservation.
2010
The Garden’s cactus and agave family collections are designated National Collections by the Plant Collections Network.
2025
The Herbarium reaches 100,000 specimens on the Garden’s founding anniversary, with an agave collected by Wendy Hodgson, Andrew Salywon and Mariana Acevedo.
Research Highlight: Six Domesticated Agaves
Herbarium Curator Emerita Wendy Hodgson, Research Botanist Andrew Salywon and volunteer researcher Jane Rosenthal identified six rare agave species first domesticated by the Hohokam and other Indigenous farmers in Arizona more than 500 years ago. Clones of the plants, found growing in long-abandoned agricultural fields, give scientists a rare, still-living record of prehistoric plant cultivation in the Southwest.
Meet the Curators
Andrew Salywon, Ph.D.
Herbarium Curator and Research Botanist
Focuses on botanical inventories, rare and endangered plants of Arizona and the Sonoran Desert, and plant systematics using traditional and molecular data.
Wendy Hodgson, M.S.
Herbarium Curator Emerita, Senior Research Botanist
A world expert on Grand Canyon flora who has discovered and named nine new agave species and authored “Food Plants of the Sonoran Desert.” Close to 40% of the Herbarium’s specimens are her own collections.
Sarah Hunkins
Collections Manager
Manages the day-to-day care of the Herbarium’s physical and digital collections, from new accessions to database records.
Access & Research Use
Specimen data, including images and location records, is free to search through SEINet. Researchers and institutions interested in loans or in-person visits can contact the Herbarium directly to arrange access.
