DOI. Fish and Wildlife Service.

See also: Ecological Risk Screening Summaries for more species summaries

USDA. APHIS. Plant Protection and Quarantine.

Includes species listed as a Federal Noxious Weed under the Plant Protection Act, which makes it illegal in the U.S. to import or transport between states without a permit.

University of California. Weed Research and Information Center.

See also: Weeds in Natural Areas for more information sheets