The Cal-IPC Inventory

The Inventory categorizes plants that threaten California's natural areas. The Inventory includes plants that currently cause damage in California (invasive plants) as well as "Watch" plants that are a high risk of becoming invasive in the future. For information about the Inventory, see "Inventory Details" below.

The Inventory represents the best available knowledge of invasive plant experts in California. Categorization is based on an assessment of ecological impacts, conducted with transparent science-based criteria and expert review. The Inventory has no regulatory authority, and should be used with full understanding of the limitations described here.

Background

Explanation of Cal-IPC ratings

About the Inventory assessment process

History of Inventory Updates (2018-present)

Download the Inventory (CSV)

  • High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
  • Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
  • Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
  • Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
  • Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.

Assessed, Not on Inventory

Plants are not listed on the Inventory when our assessment finds insignificant current impact and/or insufficient risk of becoming invasive in the future to qualify as a Watch plant. See the list of plants that have been assessed and not added to the Inventory

Pending Assessment

We maintain a list of plants that need to be assessed for current invasiveness or risk of future invasiveness. We draw from this list for periodic updates to the Inventory. See the list of plants pending assessment

Problematic Natives

A handful of native species cause ecological problems where they have been moved outside their historic range in California.
See list of problematic native plants

Using the Inventory table:

  • Click a plant’s Scientific Name to see its Plant Profile page. For the plant’s assessment, click the icon in the far right column, PAF/PRE.
  • The CDFA column lists California Dept. of Food and Agriculture weed ratings (see CDFA definitions here). A checkmark in the Hort column denotes plants that are known from horticulture; the icon in the CWM column links to the CalWeedMapper page for the plant; the icon in the ID card links to a species identification card for the plant, if available (complete listing of Species ID Cards).
  • To sort the table by any column heading (except ID Card), simply click on the column heading. To list only plants from certain Jepson Regions or Habitat Types, use the filters below.
  • “Watch” species are not currently invasive in California. Assessment has found them to be a high risk for becoming invasive in the future.
    • A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
    • B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
    • C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
    • D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
    • Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
    • * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
    • -* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.

More details

Use the buttons below to choose plants to display by region, habitat, and whether the plant is designated an invasive plant or a watch plant.

Scientific nameCommon namesRatingAlertCDFAHortCWMID cardPAF/
PRE
Acacia baileyana cootamundra wattle Watch ✔
Acacia cyclops cyclops Acacia Watch
Acacia dealbata silver wattle Moderate ✔
Acacia longifolia Sydney golden wattle Watch ✔
Acacia melanoxylon blackwood Acacia Limited ✔
Acacia paradoxa kangaroothorn Watch -*
Acacia pycnantha golden wattle Watch
Acacia saligna orange wattle Watch ✔
Acaena novae-zelandiae biddy-biddy