California Native Plant Society

Education Program

CNPS Workshop Instructors


CNPS Plant Science Training Program
James M. Andre An avid botanist and conservationist in California for 30 years, Jim has served as Director of the UC Granite Mountains Desert Research Center (GMDRC) since 1994. He is a recognized expert on the flora of the Mojave and Great Basin Deserts, author of A Flora of the Mojave National Preserve, and is currently working on a flora of the Owens Valley/Eastern Sierra. Jim’s research interests include plant demographics, floristics, and the conservation biology of rare plants. He has taught numerous university-level courses and advanced field workshops in botany, including six UC Jepson Workshops. He remains active in CNPS serving as the Senior Advisor to the CNPS Rare Plant Program.
Michelle Balk has over seven years of experience as a biological consultant in San Diego County, much of her work involving rare plants.  She earned a B.S. in Zoology from Iowa State University and a M.S. in Biology (emphasis in ecology and evolution) from The University of Akron (Ohio).  Her thesis work involved life history research on lizards, but upon moving to Southern California, she rapidly converted to botany and has never looked back.  In addition to her consulting duties, Michelle has taught several botany classes on the Southern California flora through Rancho Santa Ana Botanic Garden.

Dr. Michael G. Barbour is Professor Emeritus at the University of California, Davis. He received a PhD in Botany/Plant Ecology from Duke University in 1967 and has been a faculty member at UC Davis since then, except for periods as an invited visiting professor. During his 40 yr career he taught plant biology, forest ecology, plant communities of California, fire ecology, and plant community ecology. In 1988, the campus recognized his abilities as an instructor by awarding him a Citation for Distinguished Teaching. His research focus has been on vegetation dynamics in many California ecosystems (salt marsh, coastal dunes, vernal pools, montane conifer forests, warm desert scrub), but he has also been a co-author or co-editor of several botany and ecology textbooks. He has held elective office in two international ecology associations and been on the editorial boards of half-a-dozen journals.

Jacob Barney Received his PhD in weed ecology from Cornell University in 2006. Has published >10 peer-reviewed manuscripts, presented at >20 conferences in the US and Japan, and has been involved in teaching and extension activities on the subjects of weed biology, ecology, and management. He is currently a postdoctoral scholar at UC Davis where he leads a project on the invasive potential of biofuel crops.
Rachelle Boul has worked as a field ecologist for the last five years, throughout California. During the last three years she has worked for the Department of Fish and Game with the Vegetation, Classification, and Mapping program (VegCamp) where she has used the rapid assessment protocol during multiple projects. Within this time she has also worked closely with CNPS and has assisted with previous Rapid Assessment workshops. Rachelle has a BS in Biology with an emphasis in botany from CSU, Chico.
Jennifer Buck is a vegetation ecologist and a botanist with the CNPS Vegetation Program. She brings to CNPS extensive work experience with different plant communities across the western United States, ranging from grasslands to forests, alpine peaks to saline marshes. Prior to joining CNPS, Jennifer worked as an ecologist with The Nature Conservancy at the Cosumnes River Preserve. She has both a B.S. and a M.S. degree in Plant Biology from the University of California, Davis.
Joel Butterworth is an independent soil and wetland consultant based in Sonoma. He has over 20 years of experience conducting wetland delineations, specializing in the soil and hydrology parameters. He also has extensive experience preparing wetland mitigation plans and erosion and sediment control plans. Joel has conducted wetland delineation and hydric soil workshops and training for the University of California, Santa Barbara Extension; California Department of Water Resources; and Society of Wetland Scientists. He is currently conducting, with Geri Hulse-Stephens, a soil and groundwater monitoring study of North Coast semaphore grass in Little Lake Valley. Joel graduated from the University of California, Santa Barbara and Oregon State University.
Josie Crawford is the Training Coordinator for the Plant Science Training Program of CNPS. She has been working for CNPS since early 2005. She holds a BA and MA in Biology from Humboldt State University. Josie has worked as a botanic and environmental educator in various forms since 1992. In previous lives she made neon signs and refinished boats, furniture, and houses, and baited trawl-lines for cod-fishermen, etc.
Virginia Dains has worked as an independent plant ecologist for 20 years mapping vegetation, rare plants, and wetlands. She has also been an active volunteer in natural history docent training, lay-person and school field trips, and has led or participated in technical training in wetland plant identification, and wetland delineation classes for US FWS and the Army Corps of Engineers. She has written and illustrated taxonomic keys and reference guides for the nonbotanists. For Virginia, every plant has a story along with a name, some of which are actually true, but none of which are forgettable.
Ellen Dean is Curator of the herbarium at the UC Davis Center for Plant Diversity. Since obtaining her Ph.D. from UC Berkeley in 1995, she has collected plant specimens throughout California, including vernal pool habitats. She has over 20 years experience identifying California plants and 17 years experience teaching people of all ages how to identify plants.
Joe DiTomaso Received his PhD at UC Davis in 1986 in Botany/Weed Science and was on the faculty at Cornell University from 1987 to 1994. Currently a Cooperative Extension non-crop weed ecologist at UC Davis. His research and education programs focus on understanding various biological and ecological aspects of invasive plants, where he uses this information to develop effective management strategies. He has published over 90 peer-reviewed papers, and three weed identification books, and has presented over 600 talks on various aspects of weed science. He is also the first editor of the new journal entitled Invasive Plant Science and Management.
John Dittes is a consulting biologist with a specialty in botany, vegetation and wetland ecology. He received a B.A. in Biology from CSU, Northridge in 1989, and has since lived in northern California. John has worked with CSU Chico, the United States Forest Service, and Jones & Stokes. For the last seven years he has co-operated Dittes & Guardino Consulting with his wife Josephine. For the last 11 years John has independently presented a series of plant identification workshops for the CSU, Chico Biological Sciences Herbarium. John is an active member of the Mt. Lassen Chapter of CNPS and for more than 5 years has lead field-trips, given presentations and has served as co-chair for rare plants and programs.
Julie M. Evens is the Lead Vegetation Ecologist with the California Native Plant Society, where she has directed CNPS vegetation projects and analyzed vegetation data for the past 6 years. Previously, she worked as a crew leader for major vegetation projects in Sequoia & Kings Canyon National Parks and the central Mojave Desert. She currently manages CNPS sampling protocols and databases, coordinates vegetation sampling and training sessions, and writes reports on vegetation classification across California. Julie received her BA degrees from UC Santa Cruz and MA degree in Biology from Humboldt State University.
Jeffrey A. Hart, Ph.D. (Captain Tule) is owner and president of Hart Restoration and Hartland Nursery, located in Walnut Grove, California. Jeff holds bachelor and master degrees in botany from the University of Montana, and a Ph.D. in biology from Harvard University. Hart Restoration is a design/build restoration company that specializes in riparian and wetland habitats, erosion control projects, and includes a native plant nursery. Other enterprises include Delta Ecotours and organic vegetables.
Kerry Heise began his study of botany while growing up in the Truckee/Lake Tahoe area in the 1970's.  After receiving a B.S. in botany from the University of Nevada Reno, he spent many field seasons with the National Park Service in the Sierra Nevada and throughout Alaska.  He returned to Reno and earned a M.S. in natural resource management while working as a botanist for the Toiyabe National Forest in the ranges of Central Nevada and along the eastern Sierra.  Following that, he spent 10 years with the University of California Integrated Hardwood Range Management Program and is currently a botanical consultant based out of Ukiah, California. Kerry has taught plant identification workshops for several years.
Diana Hickson, Senior Botanist and Biogeographer, has worked in the Vegetation Classification and Mapping Program of the Department of Fish and Game for over five years. She has collected vegetation data using the Rapid Assessment methodology all over the state, and has taught numerous other people how do so. She received her undergraduate degree from UC Berkeley and graduate degree from UC Santa Barbara.
Deborah Hillyard, Staff Environmental Scientist, California Department of Fish & Game, leads large scale conservation planning efforts in California’s Central Coast. Deb’s education in biology and range ecology focused on the ecology and management of arid and semi-arid systems. She is found most commonly in the grassland and shrubland habitats of California’s Central Coast, but will appear sporadically in desert or tundra locations. Deb is familiar with many of the rare, threatened and endangered species of the Central Coast, and has facilitated conservation of their populations and habitats. She has taught sections of workshops regarding rare plants, coastal prairie, maritime chaparral, and the various laws and regulations which apply to Central Coast species and habitats.
Dr Bob Holland has studied California plant life since arriving at UC Davis for graduate school in 1972. Early work in vernal pools expanded into the broader realm of vegetation, culminating in his 1986 “Preliminary descriptions of California natural communities”, the first bibliographically driven classification of California vegetation types. He has studied sensitive plants in every California county (except Del Norte) and has mapped more than 30,000,000 acres of vegetation. An outside-the-box thinker, he enjoys integrating seemingly disparate disciplines ranging from population genetics to plate tectonics in interpreting California plant life.
Geri Hulse-Stephens is a botanical consultant in Northern California. Among her projects is a fourteen-year study of rare wetland species in the Little Lake Valley in Mendocino County. She is the rare plant coordinator for the Sanhedrin Chapter of the California Native Plant Society. She wrote and illustrated an article for Fremontia describing the flora of Mount Sanhedrin and statewide high-elevation plant distribution. In addition, she has contributed writings, illustrations and field information to several other botanical publications. She sits on the boards of the Mendocino County Resource Conservation District and the U.S. Forest Service Resource Advisory Committee. She is a graduate of the University of California, Santa Barbara.
Nick Jensen, CNPS Rare Plant Program Director, has been working for CNPS since March 2006. Nick first worked with the CNPS Vegetation Program on the Sierra Nevada Foothills, Lassen Foothills and various other projects and became the Rare Plant Botanist in 2008. Nick holds a B.S. from UC Davis in Environmental Horticulture and Urban Forestry with an emphasis in Plant Biodiversity and Restoration Ecology. Nick’s love for plants began while working in his grandmother’s garden at a very young age and he has been professionally involved in botanical research, teaching, and field work since 2000.
Dr. Todd Keeler-Wolf is an ecologist who has worked in California for over 30 years studying the vegetation and flora of virtually every terrestrial ecosystem in the state. Currently he is the Senior Vegetation Ecologist at the California Department of Fish and Game and leads their Vegetation Classification and Mapping Program. He is also program director of the California Native Plant Society’s Vegetation Program. He is co-author with John Sawyer and Julie Evens of the upcoming Second Edition of The Manual of California Vegetation and several other books and publications, including the revised UC Press California Plant Life Natural History guide, and the third edition of the Terrestrial Vegetation of California, which he co-edited with Michael Barbour and Allan Schoenherr. Todd received his undergraduate and graduate degrees at UC Santa Cruz.
Dr. Dave Keil is Professor of Biology at California Polytechnic State University in San Luis Obispo. Dave has had a lifelong interest and enthusiasm for botany. He received his B.S. and M.S. in botany from Arizona State University and his Ph.D. from Ohio State University. He teaches courses in general botany, plant taxonomy, field botany, evolution, and biogeography. He has authored scientific papers, textbooks, and study guides, and was a major contributor to the Jepson Manual and the Flora of North America. He is Curator of the Robert F. Hoover Herbarium at Cal Poly. His research interests include Asteraceae systematics and floristics of Western North America.
Guy Kyser has worked in Weed Science for 20 years.  During this time he earned a masters degree in plant ecology at UC Davis.  In many years of research with Joe DiTomaso, Guy has acquired extensive experience in rangeland and non-crop herbicide applications, techniques, and calibration.  He has given numerous talks on these topics in workshops with Cooperative Extension and Cal-IPC.
Tasha La Doux Ph.D., Botany, currently works full-time as the Assistant Director of the GMDRC and part-time as the Botanist at Joshua Tree National Park, and is a Research Associate with Rancho Santa Ana Botanic Garden. Her research interests include: reproductive biology in plants, rare plant management, and floristics; she maintains an active role in public lands management and the conservation of rare plants in the region. She is currently working on a Flora of Joshua Tree National Park.
John Menke is the Senior Vegetation Mapping Specialist at Aerial Information Systems, Inc. With over 30 years of experience, he has been the lead photo interpreter for the National Park Service’s Vegetation Mapping Program at Yosemite, Sequoia-Kings Canyon, Joshua Tree, Point Reyes and Golden Gate National Parks. He has also conducted mapping efforts for the Marin Municipal Water District, western Riverside County, the Sacramento Delta region, Napa County and numerous locations throughout California.
Kevin Merk serves as senior biologist for Rincon Consultants, an environmental consulting firm with offices in San Luis Obispo, Ventura and Carlsbad, California. Kevin’s formal training is in botany, horticulture and restoration ecology, and has worked throughout the state of California as a private consultant. Over the past ten years he has lived and worked in San Luis Obispo County. Kevin brings his professional experiences as a private consultant to the workshop, as well as his many years of botanizing the varied plant communities of the Central Coast.
Amy Merrill, PhD is the Senior Riparian Ecologist at Stillwater Sciences. Amy has more than 17 years of experience in the field of riparian and ecosystem ecology, restoration planning and design, and watershed management. Her expertise in riparian and wetland systems includes soil and ground water biogeochemistry, plant-soil interactions, and plant community composition in Sierra meadows and riparian systems. In addition, Amy has led/participated in multiple projects in the San Francisco-San Joaquin Delta and Sacramento River involving wetland restoration and planting design, monitoring, and implementation. She has also led and participated in projects to develop spatially explicit models of riparian and watershed processes in the Sierra Nevada and for the San Francisco-San Joaquin Delta, with a focus on the interface between hydrology, fluvial geomorphology, and plant community composition. Amy also has background and experience in forest and fire ecology.
Jim Nelson retired from the Department of Fish and Game in 2006 and works for various agencies and organizations as a meeting facilitator and trainer. He specializes in helping scientists and resource managers build the skills they need to be effective conserving the precious natural resources of the western United States.
Julie Kierstead Nelson has been a professional botanist since 1976, doing rare plant surveys and conservation work in Oregon and California. She has a B.S. in botany from Oregon State University and an M.S. in biology from Northern Arizona University, and worked in the herbarium at both schools. Julie worked for Berry Botanic Garden in Portland as conservation director from 1982 until 1988, developing a seed bank for rare & endangered plants of the Pacific Northwest. Since 1989 she has been Forest Botanist for the Shasta-Trinity National Forest in Redding, CA. With Gary Nakamura she edited the 2001 publication Field Guide to Selected Rare Plants of Northern California, published by the University of California. Recently she's written the content for rare plant and Klamath-Siskiyou Mountain serpentine pages on the Forest Service's national Celebrating Wildflower website, at
Bruce Orr, PhD, is the Principal/Senior Ecologist at Stillwater Sciences. Bruce has more than 25 years of experience in population and community ecology of aquatic, terrestrial, and wetland environments in the western United States. He specializes in natural resources inventory and management planning, ecological restoration, wetlands and freshwater ecology, riparian vegetation dynamics, flora and vegetation of the western United States, and aquatic entomology. He is experienced in wetland delineation and functional assessment, threatened and endangered species surveys, plant community classification and mapping, mitigation planning, and environmental impact assessment. Bruce has managed a number of complex, multi-year projects involving interdisciplinary teams conducting natural resource inventories, assessments, and watershed analysis in a variety of habitats; developing natural resource management, habitat conservation, and river corridor restoration plans; and producing environmental impact assessment documents. His current research and management focus is on riparian vegetation dynamics and restoration of river-floodplain-riparian systems.
Rob Preston received his BA in Biological Sciences and MA in Botany from CSU Chico and his PhD in Botany at UC Davis. He is currently Senior Botanist with Jones & Stokes, and over the last 17 years has traveled throughout the state to survey threatened and endangered species, delineate wetlands, and sample and map vegetation. During his 25 years studying the California Flora, he has written hundreds of technical reports, published over a dozen taxonomic and floristic papers, and is the lead author for 16 families and 50 genera in the Jepson Manual Second Edition. Rob has a particular fondness for vernal pools and has spent many Spring days studying the vernal pool flora and fauna and leading tours for friends and colleagues.
Dr. Stephen P. Rae has had a 30-yr career in natural resources planning and conservation with Napa County agencies and the California Department of Fish and Game. He received his PhD in Botany from the University of California, Davis. He is now managing partner of the consulting group MUSCI Natural Resource Assessment and President of the consulting group Institute for Environmental and Ecological Research (IEER). His teaching experiences have been numerous and mainly delivered through University of California Extension, Napa Valley Adult School, Napa Valley College, and CDFG. Topics included: Plant Ecology, Flora of Bodega Head, Mosses of California, CEQA Compliance, Sensitive Native Plant Surveys, Programming in BASIC, Wildflower Identification, Wildlife Biology, Environmental Studies, among many others.
Jon P. Rebman, Ph.D. is the Mary and Dallas Clark Endowed Chair/Curator of Botany at the San Diego Natural History Museum since 1996. Dr. Rebman is a plant taxonomist and conducts extensive floristic research in Baja California and in San Diego and Imperial Counties. His primary research interests have centered on the systematics of the Cactus family in Baja California, especially the genera Cylindropuntia (chollas) and Opuntia (prickly-pears). Recently, he published a new edition of the Checklist of the Vascular Plants of San Diego County and is working on a new specimen-based checklist for the plants of Baja California.
Fred Roberts is a botanical consultant with 25 years of field experience surveying rare plants in southern California. A graduate of U.C. Santa Barbara, Fred was the assistant curator of the Museum of Systematic Biology, managing the herbarium during the 1980’s and worked as a botanist for the U.S. Fish and Wildlife Service during the 1990’s. He is an author of several botanical books and is the Rare Plant Chair or co-chair for the Orange, San Bernardino/Riverside, and San Diego Chapters of CNPS, in addition to regularly participating in the decision process regarding additions and subtractions from the CNPS Rare Plant Inventory. Fred has taught botanical classes for the San Diego Natural History Museum and Rancho Santa Ana Botanic Garden.
John O. Sawyer, Professor of Botany, Emeritus, is an ecologist that has studied the vegetation of California for more than 40 years. He taught ecology at Humboldt State University with emphasis on understanding the vegetation patterns in northwestern part of the state. John is co-author with Todd Keeler-Wolf and Julie Evens of the upcoming Second Edition of The Manual of California Vegetation and several other books and publications. John received his undergraduate at California State University, Chico and graduate degrees at Purdue University.
Donna Shorrock is a vegetation ecologist with the CNPS Vegetation Program. She is currently assisting with documentation of rare plant communities in California. She is researching historical background on identification, ranking, and mapping of rare plant communities and she will identify, analyze, and integrate existing data of rare vegetation into documents such as in A Manual of California Vegetation. Prior to coming to CNPS, Donna was working for the National Park Service as a regional Wetlands Biologist. She earned her MS in Plant Biology from Arizona State University.
Dr. (and DSc) Aizik I. Solomeshch has been a Project Scientist at the University of California Davis, since 2001. Previously he was Director of the Geobotanical Laboratory in the Institute of Biology, a research unit within the Russian Academy of Sciences, and he was also an associate faculty member at Bashkir State University. His expertise is in vegetation ecology, in particular the description and classification of wildland vegetation types. For the past seven years he has been a member of a vernal pool research team that surveyed vernal pool vegetation throughout California and developed a classification of community types. He is a co-author of several peer-reviewed publications and of a textbook on vegetation science, lead author of a comprehensive red book summary of rare and threatened plant communities throughout Russia, and the sole author of a chapter summarizing the immense West Siberian peatlands and their contribution to the global carbon balance (2005, Cambridge University Press).
Deborah Stout joined the CNPS Vegetation Program this past spring as a Vegetation Crew Team Leader. In this capacity, she has assisted with a large-scale classification and mapping project in the Carrizo Plain National Monument. Other tasks include the management and analysis of various data sets being used to classify vegetation in the Mojave Desert, and writing and editing technical reports. Prior to joining CNPS, Deborah worked for over 5 years with various firms as an environmental consultant in the Sacramento region. Deborah holds a BA in Biology from the University of Montana, Missoula; and a BS in Ecology from the University of California, Davis.
Sula Vanderplank is the Administrative Curator of the Herbarium at Rancho Santa Ana Botanic Garden, and is currently a student at Claremont Graduate University, where she studies the Flora of San Quintín. She has taken more than 20 trips to this area during the course of her research and works in collaboration with various researchers and conservation agencies in Baja California. Sula has a Botany degree from the University of Reading (UK), and a diploma in Conservation Strategies and Solutions for Latin America, from the Technical Institute of Monterrey.
Peter Warner stumbled upon the fascinating world of botany in 1982, enthralled with a magnificent stand of Pedicularis densiflora in Sonoma County. He now works as an environmental scientist for California State Parks in Mendocino County, and enjoys passing his time studying plants and sharing his discoveries with others through teaching and volunteering. Experienced in a diversity of botanical and ecological pursuits, he’s a former CNPS chapter president and past California Invasive Plant Council board member. Quick to stoop to pull a weed or drop to the ground in reverence of elephant heads (the plant!), Peter has worked as a vegetation specialist, botanist, habitat restorationist, educator, consultant, landscaper, bureaucrat, professional musician, and cab driver. He’s got a couple of parchment documents from Sonoma State University, He’s previously taught workshops on identification of the flowering plants, the Poaceae, and the Asteraceae.

Dave Weixelman is a botanist with the U.S. Forest Service on the Tahoe National Forest, California. His interest in botany began while hiking the Colorado Rockies. Dave received his undergraduate degree in botany and his graduate degree in wildlife management from the University of Alaska, in Fairbanks. He has worked on the Chugach National Forest in Alaska where he studied the browsing habits of moose and plant succession following fire. Dave was the Forest Botanist on the Humboldt-Toiyabe National Forest where he helped develop a classification of riparian plant community types. Dave has helped teach a number of courses on sedges and riparian plants over the years. His current work includes monitoring plant composition and the health of meadows on National Forest lands in California.

John Willoughby, M.A., is a consulting botanist, recently retired from the Bureau of Land Management, where he served as California State Botanist for 28 years. He is the coauthor of two widely cited textbooks on the monitoring of plant populations and vegetation and has instructed dozens of workshops on the subject. He served as an adjunct professor at California State University, Sacramento, for more than 20 years, and has experience and training in statistical sampling techniques, nonparametric statistics, multivariate analysis, population modeling, and remote sensing of vegetation. He has designed many monitoring studies, including one of the largest and most intensive plant monitoring efforts ever implemented, involving 10 years of rare plant monitoring in the Algodones Sand Dunes.
Carol Witham has been studying vernal pool ecosystems for 20 years.  She is a recognized expert in the rare plants and animals of vernal pools, and recently served as lead taxonomist in a state-wide research project intended to classify vernal pool vegetation. She regularly presents lectures about vernal pool ecology in college and university courses and at the Continuing Legal Education, Int. biennial conference on wetlands. As a volunteer with CNPS, Carol leads the organization’s campaign to preserve vernal pools and their associated grasslands.  Carol was the editor of Ecology, Conservation, and Management of Vernal Pool Ecosystems, 1998 and author of A Field Guide to Vernal Pools, Sacramento County, 2006. She also owns and maintains the website


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