The CNPS Ranking System

CNPS Lists

CNPS has created five "lists" in an effort to categorize degrees of concern. Please see the Online Inventory for information about the number of plant taxa in each category and for more information about the species tracked as rare by CNPS. The CNPS lists are described as follows:

List 1A: Plants Presumed Extinct in California 

The plants of List 1A (less than 30 taxa) are presumed extinct because they have not been seen or collected in the wild in California for many years. This list includes plants that are both presumed extinct in California, as well as those plants which are presumed extirpated in California. A plant is extinct in California if it no longer occurs in or outside of California. A plant that is extirpated from California has been eliminated from California, but may still occur elsewhere in its range.

Astragalus pycnostachyus var. lanosissimus (Rediscovered in 1997- now on List 1B.1), photo by Nick Jensen 2006

Mimulus pictus (List 1B.2), photo by Lara Hartley 2006

Plants are placed on List 1A in an effort to highlight their plight and encourage field work to relocate extant populations. Since the publication of the fifth edition (1994), eight plants thought to be extinct in California have been rediscovered. These are Ventura marsh milk-vetch (Astragalus pycnostachyus var. lanosissimus), San Fernando Valley spineflower (Chorizanthe parryi var. fernandina), diamond-petaled California poppy (Eschscholzia rhombipetala), Mojave tarplant (Hemizonia mohavensis), water howellia (Howellia aquatilis), Howell's montia (Montia howellii), northern adder's-tongue (Ophioglossum pusillum), and Shasta orthocarpus (Orthocarpus pachystachyus). The successful rediscovery of several List 1A plants is encouraging and CNPS hopes that it will motivate professional and amateur botanists alike to search for and rediscover more List 1A species.

All of the plants constituting List 1A meet the definitions of Sec. 1901, Chapter 10 (Native Plant Protection Act) or Secs. 2062 and 2067 (California Endangered Species Act) of the California Department of Fish and Game Code, and are eligible for state listing. Should these taxa be rediscovered, it is mandatory that they be fully considered during preparation of environmental documents relating to the California Environmental Quality Act (CEQA).

List 1B: Plants Rare, Threatened, or Endangered in California and Elsewhere 

The plants of List 1B are rare throughout their range with the majority of them endemic to California. Most of the plants of List 1B have declined significantly over the last century. List 1B plants constitute the majority of the plants in CNPS’ Inventory with more than 1,000 plants assigned to this category of rarity.

All of the plants constituting List 1B meet the definitions of Sec. 1901, Chapter 10 (Native Plant Protection Act) or Secs. 2062 and 2067 (California Endangered Species Act) of the California Department of Fish and Game Code, and are eligible for state listing. It is mandatory that they be fully considered during preparation of environmental documents relating to CEQA.

List 2: Plants Rare, Threatened, or Endangered in California, But More Common Elsewhere 

Penstemon janishiae (List 2.2), photo by Cheryl Beyer

Except for being common beyond the boundaries of California, the plants of List 2 would have appeared on List 1B. From the federal perspective, plants common in other states or countries are not eligible for consideration under the provisions of the Endangered Species Act. Until 1979, a similar policy was followed in California. However, after the passage of the Native Plant Protection Act, plants were considered for protection without regard to their distribution outside the state.

With List 2, we recognize the importance of protecting the geographic range of widespread species. In this way we protect the diversity of our own state's flora and help maintain evolutionary process and genetic diversity within species. All of the plants constituting List 2 meet the definitions of Sec. 1901, Chapter 10 (Native Plant Protection Act) or Secs. 2062 and 2067 (California Endangered Species Act) of the California Department of Fish and Game Code, and are eligible for state listing. It is mandatory that they be fully considered during preparation of environmental documents relating to CEQA.

List 3: Plants About Which We Need More Information - A Review List

Salvia dorrii var. incana (list 3), photo by Steve Matson 2006

The plants that comprise List 3 are united by one common theme - we lack the necessary information to assign them to one of the other lists or to reject them. Nearly all of the plants remaining on List 3 are taxonomically problematic. For each List 3 plant we have provided the known information and then indicated in the “Notes” section of the Inventory record where assistance is needed. Data regarding distribution, endangerment, ecology, and taxonomic validity will be gratefully received by e-mailing the Rare Plant Botanist at njensencnps.org or (916) 324-3816.

Some of the plants constituting List 3 meet the definitions of Sec. 1901, Chapter 10 (Native Plant Protection Act) or Secs. 2062 and 2067 (California Endangered Species Act) of the California Department of Fish and Game Code, and are eligible for state listing. We strongly recommend that List 3 plants be evaluated for consideration during preparation of environmental documents relating to CEQA.

List 4: Plants of Limited Distribution - A Watch List

Phacelia exilis (List 4.3), photo by Lara Hartley 2005

The plants in this category are of limited distribution or infrequent throughout a broader area in California, and their vulnerability or susceptibility to threat appears relatively low at this time. While we cannot call these plants "rare" from a statewide perspective, they are uncommon enough that their status should be monitored regularly. Should the degree of endangerment or rarity of a List 4 plant change, we will transfer it to a more appropriate list.

Very few of the plants constituting List 4 meet the definitions of Sec. 1901, Chapter 10 (Native Plant Protection Act) or Secs. 2062 and 2067 (California Endangered Species Act) of the California Department of Fish and Game Code, and few, if any, are eligible for state listing. Nevertheless, many of them are significant locally, and we strongly recommend that List 4 plants be evaluated for consideration during preparation of environmental documents relating to CEQA. This may be particularly appropriate for the type locality of a List 4 plant, for populations at the periphery of a species' range or in areas where the taxon is especially uncommon or has sustained heavy losses, or for populations exhibiting unusual morphology or occurring on unusual substrates.

Threat Ranks

The CNPS Threat Rank is an extension added onto the CNPS List and designates the level of endangerment by a 1 to 3 ranking, with 1 being the most endangered and 3 being the least endangered. A Threat Rank is present for all List 1B’s, List 2’s and the majority of List 3’s and List 4’s. List 4’s may contain a Threat Rank of 0.2 or 0.3; however an instance in which a Threat Rank of 0.1 is assigned to a List 4 plant has not yet been encountered. List 4 plants generally have large enough populations to not have significant threats to their continued existence in California; however, certain conditions still exist to make the plant a species of concern and hence be placed on a CNPS List. In addition, all List 1A (presumed extinct in California), and some List 3 (need more information) and List 4 (limited distribution) plants, which lack threat information, do not have a Threat Rank extension.

Threat Ranks

• 0.1-Seriously threatened in California (high degree/immediacy of threat)
• 0.2-Fairly threatened in California (moderate degree/immediacy of threat)
• 0.3-Not very threatened in California (low degree/immediacy of threats or no current threats known)

Where did the RED Code go?