The CNPS Inventory of Rare and Endangered Plants

The CNPS Inventory of Rare and Endangered Plants (The Inventory) has served as a resource for information about California's rare plants for over 35 years. The Inventory is a credible and widely-recognized resource that plays a significant role in promoting scientific research, conservation planning, and the effective enforcement of environmental laws that deal with plant conservation. The Inventory also helps to build a foundation for stewardship and conservation by celebrating the unique richness of, and facilitating education about California's rare plants. CNPS published the first edition of its Inventory of Rare and Endangered Plants in 1974. The Inventory was published in print form a total of 6 times (the last print version, the 6th Edition was published in 2001).

The Online CNPS Inventory of Rare and Endangered Plants (8th Edition)

The Online Inventory, 8th Edition was released in December of 2010. Our primary goal for this edition was to create a more intuitive end user experience while providing substantially improved functionality; thus making work with the vital data more enjoyable, easy, and fun.

The Online Inventory is used on a daily basis by conservationists, consultants, planners, researchers, and resource managers to obtain information about California's rare plants. This information is often used to help educate landowners and public policy makers about the importance of rare plant stewardship and conservation. Online Inventory data helps to provide decision makers with the information needed to identify, protect, and manage California's unique and fragile botanical resources. Individuals preparing environmental documents (for review under the California Environmental Quality Act (CEQA)) often use the Online Inventory to help determine the potential for resource conflicts, and to develop project-specific lists of rare plants to target during botanical surveys. Conservationists and resource managers use the same information to review environmental documents and prepare public testimony to influence decision makers. As a result, the Online Inventory directly guides rare plant protection efforts, conservation planning, and land acquisition and management.

The 8th Edition could not have been completed without a significant, large contribution from a private donor, a smaller CNPS Board allocation from funds donated by the late June Bilisoly, and a number of other contributions from users of the database. CNPS offers our sincere appreciation for these financial contributions, as well as the combined efforts of many other individuals who helped with the design, development, and implementation of the project.

More information:

• CNPS Ranking System
• CNPS Status Review Process
• Fall and Summer Flowering Rare Plants of California's Deserts (PDF 49kb)

The 7th Edition of the Online CNPS Inventory of Rare and Endangered Plants

CNPS Inventory data was first made available online in 2001 with the release of the Online Inventory of Rare and Endangered Plants (Online Inventory, 7th Edition). The 7th Edition of the Online Inventory is still fully functional and available to use by following the link below.

Online Inventory, 7th Edition

The 6th Edition of the CNPS Inventory of Rare and Endangered Plants

While some of the data present in the 6th edition Inventory is out-of-date, there is still a lot of information that is extremely useful and valuable for those involved in rare plant conservation. Information present in the introductory material covers a wide range of topics that are important in the conservation of rare plant species.

Introductory Material

Below are select introductory articles from the 6th edition CNPS Inventory:

• Introduction to the 6th edition CNPS Inventory
• History of the CNPS Rare Plant Program and Inventory
• Uses of the CNPS Inventory - How use of the CNPS Inventory can promote the preservation of rare plants and their habitats.
• Numerical Analysis of This and Previous Editions - The size of California's rare and endangered flora continues to grow as this analysis of the past six editions of the Inventory demonstrates.
• Rarity in Vascular Plants by Peggy Fiedler
• Rare Bryophytes in California by James Shevock
• Bibliography for Biology and Conservation of Rare Plants by Peggy Fiedler and James Smith, Jr.
• Conserving Plants with Laws and Programs Under the Department of Fish and Game by Sandra Morey and Diane Ikeda
• The California Natural Diversity Database: California's Natural Heritage Program by Roxanne Bittman
• The Federal Endangered Species Act and Rare Plant Protection in California by Jim Bartel, Jan Knight, and Diane Elam
• Rare Plant Management on the National Forests and Grasslands in California by Bradley Powell
• Rare Plant Conservation on Bureau of Land Management Lands by John Willoughby

Updates to the CNPS Inventory, 6th Edition

Silene serpentinicola was added to the CNPS Inventory (List 1B.2) in 2005. Photo by S. Carothers.

For those who still have and use the 6th edition CNPS Inventory, you can see major changes that have been made to the Inventory since 2001 by viewing this PDF document (29kb PDF). This document lists the species that have been added to the Inventory, have had their listing status changed in the Inventory, have been deleted from the Inventory, and have had their name changed in the Inventory since the publication of the 6th edition CNPS Inventory in 2001. For the most up-to-date information on rare plant species in California, please visit the CNPS Online Inventory.

Questions or Comments?

Please contact the CNPS Rare Plant Botanist Aaron Sims at 916/324-3816 or via email at asimscnps.org. To purchase a copy of the 6th edition Inventory, visit our online bookstore or contact CNPS at 916/ 447-2677.

Taxa not Included in the 6th Edition

CNPS has tracked plants that are rare from a statewide perspective since the late 1960's with over 2,000 taxa currently considered by CNPS to be rare statewide (see CNPS' Online Inventory of Rare and Endangered Plants of California). However, one should keep in mind that if a species is not included in the CNPS Inventory, it does not necessarily mean that the species is not rare.

While CNPS strives to maintain an accurate and up-to-date list of rare plants, the size of California, the large number of unique California endemic plants, and the dynamic nature of rare plant data makes maintaining this list a challenging enterprise. There are several major reasons why a plant not included in the CNPS Inventory may still be considered rare. One should consider the issues below before making a final decision on the rarity of a plant.

• Many plants that are not rare from a statewide perspective may none-the-less be rare from a regional perspective (see Locally Rare Plants discussion).
• Species that were once considered to be too common or that were not thought to occur in California ('considered but rejected' taxa), may have become rare or have subsequently been found in California in the years since the taxon was first examined by CNPS and the information has not yet been updated. See below for a list of Considered But Rejected Taxa (CBR).
• Species that are on the list of postponed taxa may in fact be rare and would especially benefit from collection of information so that an accurate assessment of their rarity can be made. See below for a list of Postponed Taxa.
• There are also taxa that have not yet been brought to the attention of CNPS as rare or that are in the CNPS backlog of rare taxa scheduled to undergo review for inclusion in the CNPS Inventory. If you know of a plant that should be considered for inclusion in the CNPS Inventory, please submit a sponsorship form located at the bottom of this page.

A list of taxa that have been considered by CNPS but subsequently rejected for inclusion in the Inventory, as well as a list of species that have been postponed, are provided below. If you have information that any of these taxa deserve inclusion in the CNPS Inventory, please let us know by contacting CNPS Rare Plant Botanist Aaron Sims at 916/324-3816 or asimscnps.org.

Considered But Rejected (CBR) Taxa - contains a list of taxa that have been considered for inclusion into the CNPS Inventory, but were not included for various reasons.

Postponed Taxa (PDF, 17k) - contains a list of approximately 300 taxa, which were considered as possible new additions during the development of the CNPS Inventory 6th edition and our ongoing data review process, but were "postponed" due to significant taxonomic uncertainty and/or lack of information regarding distribution, abundance, rarity and/or endangerment.