California Native Plant Society
Rare Campaign

Rare Plant Program

The mission of the CNPS Rare Plant Program (The Program) is to develop current, accurate information on the distribution, ecology, and conservation status of California's rare and endangered plants, and to use this information to promote science-based plant conservation in California.

Galvezia speciosa (photo by York 1982)
Gambelia speciosa (photo by York 1982)

The Program, since its inception in 1968, has developed a reputation for scientific accuracy and integrity. The Program’s data are widely accepted as the standard for information on the rarity and endangerment status of the California flora. For this reason, The Program’s primary responsibility is the maintenance of the CNPS Inventory of Rare and Endangered Plants of California (the CNPS Inventory), which tracks the conservation status of hundreds of plant species. Please click on a link below for more specific information about various aspects of the Rare Plant Program.


The Rare Plant Status Review Process

Once a species has been identified as being of potential conservation concern, a rigorous review process ensues. The Rare Plant Botanist at CNPS evaluates existing literature, reviews herbarium collections, and communicates with experts on the species in order to gather as much information as possible on the particular species under review. Based on this information, a recommendation is then made as to whether a species merits listing by CNPS and if so, what list it should be placed on. A summary of the information gathered on the species is then put together and sent out to a statewide network of over 350 California botanists, representing state and federal agencies, consulting firms, academic institutions, CNPS and other conservation organizations. Once consensus is reached about a change amongst various members of the review groups, the species will be added to a group of pending changes, which will all be implemented and disseminated on a quarterly basis. If consensus is not reached, then a meeting will be held in order to discuss the data more fully and come to an agreement on what the best action would be to take.

Calochortus striatus (photo by Swift 1998)
Calochortus striatus (photo by Swift 1998)

Once a species has gone through the above review process, information on all aspects of the species (listing status, habitat, distribution, threats, etc.) are entered into the online CNPS Inventory. The print and online versions of the CNPS Inventory are used by thousands of professional and amateur botanists throughout the state. Consultants and planners preparing environmental documents use the CNPS Inventory to determine the potential for resource conflicts and the scope of necessary botanical surveys. Resource managers use the information to guide rare plant protection and the acquisition and management of preserve areas. Conservationists use the same data to review environmental documents and prepare testimony to educate decision-makers. Researchers use the information to evaluate trends and changes in populations of rare plants.

The Program currently recognizes more than 1600 plant taxa (species, subspecies and varieties) as rare or endangered in California (CNPS Lists 1B and 2). This constitutes approximately 20% of California’s native flora. More than 500 additional species are on the CNPS’ list of plants of limited distribution (List 4, a “watch” list) and approximately 55 additional species are on the CNPS’ list of taxa about which we need more information (List 3). The Inventory also contains information on approximately 25 native plants that are presumed to have gone extinct in California in the last 100 years (primarily because of land conversion to agriculture and urban development).

For more information on the Rare Plant Status Review Process please read How to Add, Change or Delete a Species.


The Relationship between CNPS and the California Department of Fish and Game

Lupinus constancei (photo by Imper 1983)
Lupinus constancei (photo by Imper 1983)

The Program operates under a Memorandum of Understanding (MOU) with the California Department of Fish and Game (DFG). The MOU outlines broad cooperation in rare plant assessment and protection, and formalizes cooperative ventures such as data sharing and production of complementary information sources for rare plants. To facilitate this cooperation, the Rare Plant Botanist is housed at the Sacramento office of the DFG’s Biogeographic Data Branch. CNPS and the DFG Natural Diversity Data Base (CNDDB) share all data files and rare plant information and work together on a daily basis to provide current, accurate information on the distribution, endangerment status, and ecology of California's rare flora.

Once a species has undergone the CNPS Review Process and has been added to a CNPS List, CNDDB uses the information gathered to map the rarest plant species to their precise locations. CNDDB makes this information available through RareFind or custom Geographic Information Systems (GIS) maps and digital information. While CNPS updates data more continuously, location information is reported more precisely by CNDDB.



The Program relies heavily on volunteer participation. Over 500 volunteer collaborators contribute rare plant data and review proposed changes to the CNPS Inventory. They provide a consensus view of the rarity, endangerment status, and ecology of California's rare plants. In addition, The Program receives support from volunteer Rare Plant Coordinators from each of the 33 CNPS chapters, and from many other professional and amateur botanists. The Program staff regularly provide technical assistance and rare plant information to CNPS chapters, conservation staff and volunteers for their advocacy work.

Castilleja hololeuca (photo by York 1985)
Castilleja hololeuca (photo by York 1985)

Chapter Rare Plant Coordinators serve as the Society’s local advocates for rare plant protection and conservation planning throughout California. They also conduct surveys of rare plant populations in their area. They, and other chapter members, contribute over half of the new field-based information reviewed by The Program. Rare Plant Coordinators and Conservation Chairs review development projects, participate in local planning processes, and distribute information to agency biologists and consultants. Program staff support the Rare Plant Coordinators by distributing rare plant information, proposing focused surveys for particular plant species, and maintaining the CNPS Inventory. The Program has also developed the CNPS Mitigation Guidelines Regarding Impacts to Rare, Threatened, and Endangered Vascular Plants -- a document prepared to aid CNPS Chapters in their review of local developments and conservation plans.
One of the biggest contributions from a CNPS volunteer was the development of the CNPS Online Inventory. Larry Levine, from the North Coast Chapter of CNPS, developed the online CNPS Inventory in 2001 and much time has been spent by Larry and the CNPS Rare Plant Botanist in maintaining and updating this database. The online version of the CNPS Inventory is updated quarterly and includes many useful features such as search tools, photos and maps.


Program Staff and Leadership

The Program currently has three full-time staff members: Program Manager David Magney ( , 916/447-2677 ext. 205), Catherine Curley, Assistant Botanist (E-mail: ) and Rare Plant Botanist Aaron Sims ( , 916/324-3816). Aaron is responsible for implementing the CNPS Review Process as well as maintenance of the CNPS Inventory and dissemination of data. He also assists with state and federal listing and other rare plant conservation work as time allows. Aaron conducts thorough research, draft status review documents, and work on a multitude of other tasks that pertain to the Program. Aaron is assisted by a half-time rare plant botanist Kaitlyn Green. The Rare Plant Coordinator runs the Rare Plant Treasure Hunt, which focuses on searching for rare plants that we need current information on to better determine how rare they are and what conservation measures are needed to prevent them from extinction. Mr. Magney, as Rare Plant Program Manager, oversees all of the Rare Plant Program projects.


Xylorhiza cognata
Xylorhiza cognata (photo by Sims 2011)

The Rare Plant Program Committee

Developed in January of 2009, the Rare Plant Program Committee (RPPC) provides expertise, on the behalf of the CNPS Rare Plant Program, related to the science and conservation of rare plants in California. A key role of the RPPC is to assist the CNPS Rare Plant Botanist in making decisions relating to the Program including (but not limited to) those involving complex taxonomic issues related to rare plant status reviews, status review procedures, changes to the CNPS Rare Plant Survey Protocols, and/or changes to the CNPS Online Inventory of Rare and Endangered Plants.

The CNPS Rare Plant Program Committee:
Rare Plant Program Senior Advisor
Jim André

Committee Chair
Heath Bartosh
Committee Members
Jim André
Roxanne Bittman
Mark Elvin
Naomi Fraga
Lawrence Janeway
Nick Jensen
Kristi Lazar
Julie Kierstead Nelson
Cheri Sanville
Shannon Still
Tim Thomas
Committee Alternates
Rob Preston


Rare Plant Program Contacts

Fritillaria pluriflora - Ackley 1987
Fritillaria pluriflora (photo by Ackley 1987)

Rare Plant Program, California Native Plant Society
2707 K Street, Suite 1
Sacramento, CA 95816

David Magney, Rare Plant Program Manager
Phone: (916) 447-2677 ext 205
Fax: (916) 447-2727

Aaron Sims, Rare Plant Botanist
Phone: (916) 324-3816
Fax:     (916) 447-2727

Alison Colwell, Assistant Rare Plant Botanist

Catherine Curley, Assistant Botanist, Rare Plant Treasure Hunt Coordinator
Phone: (916) 447-2677 ext 212

Kaitlyn Green, Assistant Rare Plant Botanist
Phone: (916) 322-1869

Steven Serkanic, Assistant Rare Plant Botanist
Phone: (916) 447-2677 ext 218


Copyright © 1999-2019 California Native Plant Society. All rights reserved. Contact Us | Privacy