Hawaii-Pacific Weed Risk Assessment [HP-WRA] is a research project by Curt Daehler (University of Hawaii) and Julie Denslow (USDA Forest Service) that has been supported by funding from the USDA Forest Service and from the Hawaii Division of Forestry and Wildlife Urban and Community Forestry program.  The WRA scoring system was originally developed in Australia and New Zealand for the evaluation of plants being imported. The intent of the HP-WRA research project is to identify plants that pose a high weed risk in Hawaii and other Pacific Islands.

The HP-WRA score does not measure actual invasiveness or economic or ecological harm in the field. Rather, a designation of H(HPWRA) is a prediction that a species will become invasive . The HP-WRA does not measure species benefits in terms of economic, ecological, public health, medicinal, historic, community, cultural, tourism, and esthetic value; nor does it determine if a suitable alternative species exists. 


The HP-WRA only considers published information on invasiveness in Hawaii or elsewhere and it does not include an actual "in-the field" evaluation of current impacts in Hawaii. Another evaluation protocol called the Hawaii Exotic Plant Evaluation Protocol (HEPEP) is being developed to provide a current field evaluation of species that have been designated H(HPWRA).

The HP-WRA ratings have no regulatory authority and the HP-WRA "list" is not an official State list of invasive plants. By statute, the Hawaii Department of Agriculture is solely responsible for determining which plant and animal species are prohibited or permitted into the State (Hawaii Administrative Rules 4:68:1 - 'Noxious Weed Rules'). To determine which species are prohibited in Hawaii, please consult the official State of Hawaii List of Plant Species Designated as Noxious Weeds.

To download the full assessment for any species, please use our search interface.