Who We Are

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.



Sean Carson

Rare Plant Technician

photo of Sean CarsonAs the Rare Plant Technician, Sean works to conserve California's rare and endangered flora. His work includes surveying and documentation of rare plants as well as seed collection for long term conservation, research, and restoration. Sean received his B.A. in Environmental Studies at California State University, San Bernardino. Sean has many years of field experience working in restoration ecology, where he worked in the San Bernardino National Forest before moving to the Channel Islands and eventually to the California Central Coast.

Research interests: Rare plant conservation, science communication, rare plant germination, conservation seed banking, rare plant restoration.

Kylie Etter, M.S.

Conservation Technician

photo of Kylie EtterAs the Conservation Technician, Kylie works with the conservation staff at the Garden on various projects focusing on insect-plant interactions, habitat restoration and monitoring, and rare plant conservation research. Kylie earned her B.S. in Ecology and her M.S. in Biology from the University of California, San Diego. Her M.S. research focused on understanding the effect of non-native fennel on pollinator visitation to the Santa Cruz Island buckwheat. She has field experience, mainly focused on plant-pollinator interactions, across the canyons of San Diego, on Santa Catalina Island and on Santa Cruz Island.

Research interests: Invasion biology, Restoration ecology, Pollination biology, Plant-pollinator interactions, Community science

Sarah Cusser

Terrestrial Invertebrate Conservation Ecologist

photo of Sarah CusserAs one of the Terrestrial Invertebrate Conservation Ecologists, Sarah works to better understand, conserve, and restore insect communities and the essential ecosystem services they provide in natural, agricultural, and urban habitats. In the past, Sarah has investigated pollination and decomposition services provided by insects in Texas, Michigan, New Jersey, and Pennsylvania and worked on habitat restoration projects in California, Vermont, and Ohio. Sarah received her PhD in Evolution, Ecology and Behavior from University of Texas, Austin, her master’s in Evolution Ecology and Organismal Behavior from the Ohio State University, and a B.A. in Biology from Pomona College.

Research interests: Landscape Ecology, Restoration Ecology, Conservation, Ecosystem Services, Pollination Ecology

Zach Phillips

Invertebrate Ecologist

photo of Zach PhillipsZach is an ecologist, entomologist and naturalist. He studies invertebrate ecology and diversity in California, from the Channel Islands to residential backyards. He explores invertebrate communities associated with plants and those hidden in plain sight, including communities of insects and spiders that live in dead wood, bird nests, beach wrack and ant colonies. Zach received his B.S. in Zoology from U.C. Santa Barbara and his Ph.D. in Integrative Biology from U.T. Austin, where his research focused on symbionts of ant colonies (“myrmecophiles”), including a miniature cockroach that lives with leaf-cutter ants, Attaphila fungicola, and an invasive ant-mimicking spider that feeds on ant heads, Falconina gracilis.

Research interests: Entomology, ecology, natural history, behavioral ecology, symbioses, urban ecology, invasion biology, island biogeography, community science, science writing, myrmecophiles

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.

Research interests: Botany, conservation genetics, evolutionary biology, floristics, herbarium curation, island biogeography, phylogenetics, taxonomy, Boraginaceae, community science, Dudleya, Montiaceae

Caitlin Hazelquist

Laboratory Technician

Photo of Caitlin Hazelquist

As a lab technician in the Plant Genetics lab, Caitlin does PCR, prepares samples for sequencing, and helps curate the Garden’s genetic database. She earned her B.S. in Biology, from California State University San Bernardino, where a floristics class kicked off her love for CA native plants. She gained a love for fieldwork performing plant ecophysiology research on two local sage species, and an enthusiasm for lab work assisting molecular ecology projects on an endangered plant, and native fish. Caitlin is especially fascinated by plant-environment interactions; how environmental pressures shape plant physiology, genetics, and distribution, and how plants in-turn influence their environment.

Research interests: Plant physiology, ecology, molecular biology, genetics, rare plants, conservation

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.

Research interests: Landscape ecology, restoration ecology, invasion biology

Kristen Lehman, Ph.D.

Conservation Geneticist and Lab Manager

Photo of Kristen Lehman, Ph.D.Kristen oversees the Plant 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.

Research interests: Floristics, plant systematics, DNA barcoding and meta-barcoding, population genomics, phylogenomics/phylogenetics, taxonomy, Boraginales, Dudleya

Josie Lesage, Ph.D.

Applied Ecologist

photo of Josie LesageJosie works to map, conserve, and restore California habitats using ecological theory as a guide. She has a Ph.D. in Environmental Studies from the University of California, Santa Cruz, where she studied long-term management and community change in California’s coastal prairies. As the Garden’s Applied Ecologist, she is interested in understanding how local ecosystems respond to disturbance and restoration intervention, and in building a community of volunteer scientists to steward our local habitats. She is currently involved in several projects related to invasive plant management and ecosystem recovery following fire.

Research interests: Restoration ecology, fire ecology, community science, invasive species management

Kevin Mason

Rare Plant Technician

Photo of Kevin MasonAs a rare plant technician, Kevin works to conserve and restore California’s rare and endangered plant populations. Kevin makes seed collections of rare plants, which are used for restoration projects and seed banking. Kevin has a B.S. in Botany and Plant Pathology from Oregon State University, and has worked for different agencies, monitoring plants across the west coast. Most of Kevin’s field work experience has been in Oregon and Southern California. He is especially interested in traditional uses of plants, and how indigenous land management practices, such as prescribed fire and select harvesting, can influence biodiversity and plant population sizes.

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.

Research interests: Lichenology, community composition, lichen ecology, lichen conservation

Isabel Rivera

Laboratory Technician

Photo of Isabel RiveraAs a Plant Genetic Laboratory Technician, Isabel works in the Plant Genetics Lab where she performs DNA extractions and quantitation. Additionally, she helps curate the Garden’s tissue bank by preserving field collections with their associated metadata. Isabel has her B.S in Biological Sciences from California State University Channel Islands. She interned at the Smithsonian Center for Conservation Genomics laboratory where she used non-invasive genetic techniques to assess the impact of canid predation on the endangered desert tortoise (Gopherus agassizii). She also has experience in conducting research on the effects of climate change on parasitic bees and their hosts at the Rocky Mountain Biological Laboratory, as well as conducting research on various projects on Santa Cruz Island. She previously volunteered with the Santa Barbara Botanic Garden in the living collections, where she performed plant identification and tagging, and is very excited about being back at the Garden working to study and protect California’s native flora.

Research interests: Botany, Conservation Genetics, Tissue Curation, Science Communication

Heather Schneider, Ph.D.

Rare Plant Biologist

Schneider, Heather, Ph.D.Heather oversees the rare plant conservation program, which includes conducting research, implementing conservation and recovery actions, managing the conservation seed bank, and providing outreach and education opportunities focused on California’s rare plants. Heather’s research interests and experience in plant ecology, seed banks, conservation, invasive plants and evolutionary biology. She earned a PhD in botany and plant sciences 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 before joining the Garden. Heather has been working to understand and protect the California flora since 2005.

Research interests: Seed banking, rare plant conservation, germination, rare plant reintroduction, plant ecology, science communication



Research Associates

Kristina M. Gill, Ph.D.

Research Associate

photo of Kristina Gill, Ph.D.Kristina M. Gill is an archaeobotanist and archaeologist working primarily in island and coastal areas of central and southern California. She completed her PhD in anthropology at the University of California Santa Barbara in 2015. Her research focuses on ancient plant use, subsistence, and settlement patterns among the Island Chumash/Tongva and their ancestors, who inhabited the islands off the coast of southern Alta California for more than 13,000 years. She combines historical ecological data from archaeological sites and Traditional Ecological Knowledge to inform modern land management and restoration practices, especially in the face of climate change.

Barbara Holzman, Ph.D.

Research Associate

photo of Barbara Holzman, Ph.D.Dr. Holzman studies vegetation dynamics. Her California research foci have included Point Reyes conifer regeneration, Farallon Islands vegetation change and plant invasions, blue oak woodland regeneration, and conservation of Ione endemic plants. She co-founded the Environmental Studies program at San Francisco State University, where she was a professor of Geography until her retirement in 2016. She received her PhD from U.C. Berkeley.

Steve Junak

Research Associate, SBBG Botanist Emeritus

photo of Steve Junak

Steve retired from his longtime position as the Garden’s Herbarium Curator in 2013. He is an active researcher and expert on the flora of the islands of California and Baja California.  Steve holds an M.A. in botany, has led field trips for more than 25 years, and has co-authored several books on the Channel Islands including A Flora of San Nicolas Island and Flora of Santa Cruz Island.

Tom Mulroy, Ph.D.

Research Associate

Photo of Tom Mulroy, Ph.D.Tom is a botanist/plant ecologist with a long-held research interest in Dudleya and botany of Baja California, Mexico.  He joined the Botanic Garden following a career in environmental consulting based in the Santa Barbara area and has wide-ranging field experience in arid and semiarid environments in the southwestern United States and adjacent Mexico.  Tom earned his B.A. in Zoology from Pomona College, his M.S. in Biology from the University of Arizona, and his Ph.D. in Ecology and Evolutionary Biology from the University of California, Irvine.

Elizabeth Painter, Ph.D.

Research Associate

Photo of Elizabeth Painter, Ph.D.Dr. Elizabeth Painter holds an M.A. in botany and a Ph.D. in ecology from Colorado State University and is also a Research Associate at UC Berkeley. She is a range ecologist with strong interests in conservation, and is a contributor to the Jepson Manual and The Jepson Desert Manual. Beth is a recognized expert on the impacts of grazing on rare and endangered plant species in rangelands.

Christian Schwarz

Research Associate

Christian SchwarzChristian Schwarz studied Ecology and Evolution at UC Santa Cruz, where his interest in the world of fungi became irrevocable – their seemingly endless forms (from the grotesque to the bizarre to the sublime) feed his curiosity. He spends his time seeking, photographing, collecting, teaching about, and publishing research on the macrofungi of California and Arizona. His work with SBBG is currently focused on assembling a mycoflora for the California Channel Islands. At large, he works primarily on the taxonomy of macrofungi, as well as documenting patterns of phenology and biogeography through long-term monitoring efforts. He is passionate about biodiversity in general, and in community science (especially iNaturalist!). He has served on the IUCN Working Group for North American Fungi, is coauthor of Mushrooms of the Redwood Coast, and is a Research Associate at the Norris Center for Natural History (UCSC) as well as at the Santa Barbara Botanic Garden.

Shirley Tucker, Ph.D.

Research Associate

Photo of Shirley Tucker, Ph.D.When Shirley retired from Louisiana State University and began her relationship with the Botanic Garden in 1995, she brought her immense passion and knowledge of plants, as well as her extensive collection of lichens. She has published over 140 papers on floral morphology, plant systematics, and the lichens of California. Among her many notable achievements and awards, Shirley was president of both the Botanical Society of America and the American Society of Plant Taxonomists. Shirley received her Bachelor’s and Master’s degrees at the University of Minnesota, and her PhD from the University of California, Davis.

Greg Wahlert, Ph.D.

Research Associate

Photo of Greg Wahlert, Ph.D.Dr. Wahlert is the Tucker Curator of Biodiversity Collections and Botanical Research at the Cheadle Center for Biodiversity and Ecological Restoration at UCSB. His primary research interests are floristic studies in central California, phylogeny and diversification of the manzanitas (Arctostaphylos) and lupines (Lupinus), systematics of the Violet Family, and taxonomic revision of various plant groups from Madagascar, including Rinorea (Violaceae), Grewia (Malvaceae), and Polygala (Polygalaceae).

Cam Williams, Ph.D.

Research Associate

Photo of Cam Williams, Ph.D.Cam has been botanizing since 1996. He really likes epiphytes, lichens, community ecology, wood anatomy, tree architecture, forest structure, forest canopy ecology, and the dynamics of plant water use. He earned undergraduate and master’s degrees from Humboldt State University, and a PhD from the University of California, Berkeley. Cam is also a Research Associate in the Gotsch Lab at Franklin and Marshall College, studying the physiological ecology of epiphyte communities in the cloud forests of Monteverde, Costa Rica. He works extensively with the Garden’s lichenologist.

Dieter Wilken, Ph.D.

Research Associate

Photo of Dieter Wilken, Ph.D.Dieter retired as Director of Research and Conservation in 2013 after 20 years of service at the Garden. Before coming to the Garden, Dieter was a professor at Colorado State University, and manager of the Jepson Manual project at UC Berkeley (1990-1993). Dieter received his undergraduate degree in botany from California State University, Los Angeles, and his doctoral degree from the University of California, Santa Barbara. Currently, he works in the Garden herbarium assisting database and imaging efforts, completing taxonomic treatments for the Flora of North America, and continuing to serve as an emeritus member of the California Native Plant Society’s Rare Plant Committee.