"Emergent” invasive plants are non-native species that have appeared recently in OC, are not yet widely distributed here, and are known or presumed to spread readily. 
  • They are of particular concern because they pose unknown or likely future competition to our native flora.
  • They are of particular priority because, as their populations are still small, they have the greatest potential to be effectively controlled or even eradicated.

OC-CNPS members can assist in resolving these challenges by providing Early Detection and Rapid Response:

  • Trained “eyes on the ground” to report new populations of priority emergent weed species.
  • Facilitation of coordination of land managers, land owners and potential labor forces for response and control, both within and across boundaries.
  • Volunteer labor to remove priority weed populations that may otherwise not be managed.


Join us! Contact us at: 

- be notified of OC-CNPS-organized Rapid Response Weed Pulls.
- tackle an invasive plant site infestation.
- provide follow-up monitoring of areas under invasive plant management.
- adopt a trail or area to search for and report new invasions.
- help with outreach, communications, land managers, lots more.


OC-CNPS’ Emergent Invasives Committee has developed a list of emergent weeds to guide Chapter members.
  • The list is dynamic, changing as emergent populations become known and controlled and new ones are found. 
  • It contains a manageable number of emergent weeds.
  • It may contain:
  • Species that OC-CNPS has given top priority due to their local distribution, invasiveness, and ability to negatively impact native habitat.
  • Other locally occurring priority species that will be evaluated regularly.
  • Potentially invasive species with unknown status.
  • New potential invaders that have not yet been observed in Orange County.
By becoming familiar with these emergent weeds, and accurately identifying and reporting their occurrences, you can make a significant contribution to the protection of OC’s natural areas from invasive plants.

 Each species’ known OC locations are listed in Known Locations & Status Updates.  If you find one in a new location, please see Reporting an Invasive Plant and immediately report your find to .

OC-CNPS also:

  • Directs ongoing treatment activities at specific sites throughout Orange County. These include emergent invasives and other non-native invasive plants.
  • Recognizes that a number of other weed species are high priorities regionally, but that its own capacity to deal with those wide-spread, common weeds is limited.


Additional resources:

  • See the PowerPoint presentation presented by OC CNPS at the Oct. 2015 Cal-IPC Annual Symposium here
  • See the handout from the Invasive Plant Mapping Workshop conducted on July 7, 201here.
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