Hypericum perforatum L. (ITIS)
St. Johnswort, St. John's wort, common St. Johnswort, Klamath weed, common goatweed, tipton weed
Eurasia and North Africa (Zouhar 2004)
1700s (Zouhar 2004)
Introduced as an ornamental and as a medicinal herb (Klein 2011)
Crowds out native species and forage on pasturelands; toxic to livestock (Klein 2011; Zouhar 2004)
Distribution / Maps / Survey Status
The section below contains highly relevant resources for this species, organized by source.
Council or Task Force
State and Local Government
Integrated Taxonomic Information System. Hypericum perforatum. [Accessed Sep 25, 2023].
Klein, H. 2011. Common St. Johnswort (PDF | 128 KB) University of Alaska Anchorage, Alaska Exotic Plants Information Clearinghouse.
Zouhar, K. 2004. Hypericum perforatum. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.