Who are we?

Our departmental mission: We serve as conservation leaders, by studying and advocating for native plants, communicating their value, and convening people in support of them.

Stephanie Calloway

Conservation Technician

photo of Stephanie CallowayStephanie works with conservation staff at the Garden on various projects focusing on insect-plant interactions, rare plants, and restoration. Stephanie has a B.S in Entomology from the University of California, Davis. She has diverse work experience, ranging from working with tardigrades to mangrove gastropods, but most of her work has focused on California plants. Stephanie is currently interested in documenting plant-pollinator interactions within our project systems. She has worked in several regions across California, including the Sierra Nevada, Channel Islands, and Mojave Desert for nearly a decade.

Matt Guilliams, Ph.D.

Ken and Shirley Tucker Plant Systematist

Curator of the Clifton Smith Herbarium

Photo of Matt Guilliams, Ph.D.

Matt is a plant systematist and curator of the Garden's Clifton Smith Herbarium. As a botanist/plant systematist, his overall focus is the study of the flora of California, which includes floristics, biodiversity description, inferring evolutionary patterns, and conservation genetics of rare plants. Matt earned his B.S. and M.S. in Evolutionary Biology at San Diego State University and his Ph.D. in Integrative Biology from U.C. Berkeley. He has been working as a botanist in the state since 1998.

Denise Knapp, Ph.D.

Director of Conservation and Research

photo of Denise Knapp Ph.D.Denise oversees the Conservation program at the Garden, including all biodiversity, rare plant, restoration, and outreach/advocacy work, and conducts ecological research. Denise has a Ph.D. in Ecology from the University of California, Santa Barbara and an M.A. degree in Geography from the University of California, Los Angeles. She has worked on vegetation, fire ecology, invasive species, habitat restoration, and rare plant projects; her current focus is plant-insect interactions. She has worked as a plant ecologist in California (particularly the Channel Islands) for nearly two decades, including the consulting, University, and nonprofit worlds.

Kristen Lehman, Ph.D.

Conservation Geneticist and Lab Manager

Photo of Kristen Lehman, Ph.D.Kristen oversees the conservation genetics lab at the Garden. She integrates field studies, molecular tools and histological techniques to document biodiversity and understand the interplay of ecological and evolutionary effects on plants of conservation concern. After receiving a M.S. at San Diego State University, Kristen earned her Ph.D. in Botany at Rancho Santa Ana Botanic Garden and worked at the Smithsonian Museum of Natural History in the plant DNA barcoding lab. She has worked with California native plants since 2006.

Rikke Reese Naesborg, Ph.D.

Tucker Lichenologist and Curator of the Lichen Herbarium

Photo of Rikke Naesborg, Ph.D.Rikke is the Garden lichenologist and curator of the Garden’s lichen herbarium. She is interested in investigating lichen community composition and ecology in order to identify why different lichen species are distributed differently across the landscapes. Another major interest is conservation of lichens; a complicated task that is only possible by expanding knowledge of lichen distribution and ecology. Rikke received her B.S. and M.S. at University of Southern Denmark and went on to earn a Ph.D. in systematic botany from Uppsala University in Sweden. She has lived in California since 2011.

Heather Schneider, Ph.D.

Rare Plant Biologist

Heather Schneider, Ph.D.Heather oversees the rare plant program, including conducting research, managing the conservation seed bank, and participating in outreach related to California's rare plants. Heather has been studying California's flora for over 12 years. She has interest and experience in plant ecology, seed banks, conservation, invasive plants and evolutionary biology. Heather has a PhD from the University of California, Riverside, worked as an Ecologist for the US Geological Survey and was a postdoctoral scholar at the University of California, Santa Barbara.