The following lists invasive plants species that currently exist in the Mattole watershed, as well as species that have not yet been identified in the Mattole but may pose a threat of spreading into this watershed.

Click on plant names for more information about each species.

These plant species have been classified according to their current and potential threat to the Mattole as well as through consultations with BLM, NPS, and CalEPPC lists. Those with ** do not currently exist in the Mattole, but have been spotted in neighboring watersheds.

List A: This list includes highly aggressive invasive species that pose the greatest ecological and economic threats to the Mattole watershed. These high priority species will be the focus of most removal projects.

List B: The species on List B have also been identified in the Mattole but cause a lesser degree of ecological damage. These particular plants may not be the focus of removal efforts but still have the potential to spread rapidly. Therefore, many of these species infestations will be monitored closely.

Red Alert: This list consists of species that have the potential to spread explosively throughout the watershed, causing large-scale dramatic ecological changes. The species on this list have not yet been identified in the Mattole. European beachgrass has existed in the King Range but all known infestations have been removed. If any of the Red Alert species are found in the Mattole, alert local specialists immediately.