Invasive Plant Mapping


CalWeedMapper displays statewide maps of invasive plants and provides management recommendations.

Mapping invasive plant populations is critical for strategic management and monitoring. It is also essential for effective early detection. Knowing where a plant currently grows is the foundation for knowing where to survey for new occurrences.

Cal-IPC supports a range of mapping tools for natural resource managers in California, including CalWeedMapper, WHIPPET and Calflora (described below). These tools work together. Data submitted to the Calflora occurrence database provide a foundation for CalWeedMapper (for setting regional priorities) and WHIPPET (for setting population-level priorities). We encourage land managers to submit their management records once a year, and early-detection observations immediately.


CalWeedMapper is an online decision-support tool developed by Cal-IPC to help regional partners set effective landscape-level strategies. It shows statewide distribution, spread and management for all invasive plant species on the Cal-IPC Inventory. For any user-selected region, CalWeedMapper recommends species to consider for eradication, surveillance, or containment strategies. CalWeedMapper also includes maps of suitable range for some plants based on climate, with projections for how that range may shift in the future. Go to CalWeedMapper



WHIPPET is a tool to help land managers prioritize eradication efforts.

WHIPPET is an online tool designed to prioritize invasive plant populations for eradication. The tool allows the user to select an area of interest and a set of invasive plant species to consider. WHIPPET then ranks the populations based on a range of factors, such as its location and estimated cost to control. To use WHIPPET, population mapping data must be in Calflora. Go to WHIPPET


Calflora is an online database of plant observations. Whether you have a single invasive plant observation or an entire GIS dataset, your data belongs in Calflora where you can use this data in various powerful ways and the information updates CalWeedMapper nightly. Go to Calflora

Cal-IPC works closely with Calflora to support invasive plant mapping in California. We encourage land managers to submit potential “early detection” observations to Calflora immediately, and to share weed mapping data with Calflora on a regular basis. We actively support Calflora’s development of the Weed Manager tool. We also work to integrate California’s mapping data with national systems like EDDMapS. Sharing your data online is a way to help us all be more effective!

Ways to submit your data:

Ways to help close data gaps:

  • Confirm mystery populations and update Calflora/CalWeedMapper (instructions)
  • Mark “management status” for populations you work on (instructions)

“How To” documents

  • How to collect field data with a recreational grade GPS (instructions in progress)
  • How to collect field data using Calflora’s Observer Pro for Android (instructions)
  • How to collect field data using Calflora’s Observer for iPhone (instructions)
  • How to submit a voucher specimen (instructions)
  • How to engage citizen scientists (instructions)

Mapping Resources

BIOS – BIOS is a statewide California database and mapping system designed to enable the management, visualization, and analysis of biogeographic data collected by the California Dept. of Fish and Wildlife and its partner organizations.

EDDMapS – Started in 2005 with a Southeastern U.S. focus, is now providing distribution data on invasive species across the U.S. See also EDDMapS West.

iMap Invasives – Online tool for invasive species reporting and data management nationwide.

North American Invasive Species Management Association (NAISMA) – National data standards for mapping invasive plants.

California Geoportal – The first place to look for California GIS layers.