Hypericum perforatum - L.
Common St. John's-wort
Other English Common Names: Klamath Weed
Other Common Names: common St. Johnswort
Taxonomic Status: Accepted
Related ITIS Name(s): Hypericum perforatum L. (TSN 21454)
Unique Identifier: ELEMENT_GLOBAL.2.153959
Element Code: PDCLU031A0
Informal Taxonomy: Plants, Vascular - Flowering Plants - St. John's-Wort Family
 
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Theales Clusiaceae Hypericum
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Hypericum perforatum
Conservation Status
Help

NatureServe Status

Global Status: GNR
Global Status Last Changed: 22Mar1994
Rounded Global Status: GNR - Not Yet Ranked
Nation: United States
National Status: NNA
Nation: Canada
National Status: NNA (31Jul2016)

U.S. & Canada State/Province Status
United States Arkansas (SNA), California (SNA), Colorado (SNA), Connecticut (SNA), Delaware (SNA), District of Columbia (SNA), Georgia (SNR), Hawaii (SNA), Idaho (SNA), Illinois (SNA), Indiana (SNA), Iowa (SNA), Kansas (SNA), Kentucky (SNA), Louisiana (SNA), Maine (SNA), Maryland (SNA), Massachusetts (SNR), Michigan (SNA), Minnesota (SNA), Mississippi (SNA), Missouri (SNA), Montana (SNA), Nebraska (SNA), Nevada (SNA), New Hampshire (SNA), New Jersey (SNA), New York (SNA), North Carolina (SNA), Ohio (SNA), Oklahoma (SNA), Oregon (SNA), Pennsylvania (SNA), Rhode Island (SNA), South Carolina (SNA), South Dakota (SNA), Tennessee (SNA), Texas (SNA), Vermont (SNA), Virginia (SNA), Washington (SNA), West Virginia (SNA), Wisconsin (SNA), Wyoming (SNA)
Canada Alberta (SNA), British Columbia (SNA), Manitoba (SNA), New Brunswick (SNA), Newfoundland Island (SNA), Nova Scotia (SNA), Ontario (SNA), Prince Edward Island (SNA), Quebec (SNA)

Other Statuses

NatureServe Global Conservation Status Factors

Other NatureServe Conservation Status Information

Distribution
Help
U.S. States and Canadian Provinces
Color legend for Distribution Map
NOTE: The distribution shown may be incomplete, particularly for some rapidly spreading exotic species.

U.S. & Canada State/Province Distribution
United States ARexotic, CAexotic, COexotic, CTexotic, DCexotic, DEexotic, GA, HIexotic, IAexotic, IDexotic, ILexotic, INexotic, KSexotic, KYexotic, LAexotic, MA, MDexotic, MEexotic, MIexotic, MNexotic, MOexotic, MSexotic, MTexotic, NCexotic, NEexotic, NHexotic, NJexotic, NVexotic, NYexotic, OHexotic, OKexotic, ORexotic, PAexotic, RIexotic, SCexotic, SDexotic, TNexotic, TXexotic, VAexotic, VTexotic, WAexotic, WIexotic, WVexotic, WYexotic
Canada ABexotic, BCexotic, MBexotic, NBexotic, NFexotic, NSexotic, ONexotic, PEexotic, QCexotic

Range Map
No map available.

Ecology & Life History Not yet assessed
Help
Economic Attributes
Help
Economic Uses: MEDICINE/DRUG
Management Summary Not yet assessed
Help
Population/Occurrence Delineation Not yet assessed
Help
Population/Occurrence Viability
Help
U.S. Invasive Species Impact Rank (I-Rank)
Help
Disclaimer: While I-Rank information is available over NatureServe Explorer, NatureServe is not actively developing or maintaining these data. Species with I-RANKs do not represent a random sample of species exotic in the United States; available assessments may be biased toward those species with higher-than-average impact.

I-Rank: High/Medium
Rounded I-Rank: High
I-Rank Reasons Summary: Hypericum perforatum, widely recognized by it's common name, St. John's Wort, is cultivated for both herbal and aesthetic qualities. Unfortunately, it has also escaped and is threatening natural areas in most areas of the US. Specific negative effects are associated with a loss of biodiversity resulting from the dense monocultures that can be formed. Infestations can be treated if caught early, else, the prolific reproductive ability of H. perforatum, will prevent easy and inexpensive management.
Subrank I - Ecological Impact: Medium/Low
Subrank II - Current Distribution/Abundance: High
Subrank III - Trend in Distribution/Abundance: High/Medium
Subrank IV - Management Difficulty: Medium
I-Rank Review Date: 15Sep2004
Evaluator: Fellows, M.
Native anywhere in the U.S?
Native Range: Throughout Europe (e.g. Denmark, France, Yugoslavia), northern Africa (e.g. Canary Islands, Sudan) and Asia (e.g. China, India, Russia) (GRIN 2001; Weber 2003).

Download "An Invasive Species Assessment Protocol: Evaluating Non-Native Plants for their Impact on Biodiversity". (PDF, 1.03MB)
Provide feedback on the information presented in this assessment

Screening Questions

S-1. Established outside cultivation as a non-native? YES
Comments: (Kartesz 1999).

S-2. Present in conservation areas or other native species habitat? Yes
Comments: An invasive of natural areas in Washington (NWCB 2003).

Subrank I - Ecological Impact: Medium/Low

1. Impact on Ecosystem Processes and System-wide Parameters:Medium significance/Insignificant
Comments: No significantly negative impacts on processes reported.

2. Impact on Ecological Community Structure:Moderate significance
Comments: Forms extensive and dense colonies (Weber 2003).

3. Impact on Ecological Community Composition:High significance
Comments: Established plants compete successfully to eliminates native vegetation (Weber 2003). May form monocultures (NV Project WEEDS).

4. Impact on Individual Native Plant or Animal Species:Unknown
Comments: Toxic, if eaten by livestock (NWCB 2003).

5. Conservation Significance of the Communities and Native Species Threatened:Medium/Low significance
Comments: In grass- and woodlands, riverbanks and disturbed areas (Weber 2003). Prefers dry sandy or gravelly soils in pastures, pinyon-juniper woodlands, foothill forests, waste places, and on roadsides (NV Project WEEDS).

Subrank II. Current Distribution and Abundance: High

6. Current Range Size in Nation:High significance
Comments: Found throughout most of the continental US with the exception of the southwest (AZ, NM, UT) and southeast (AL, FL) (Kartesz 1999; NRCS 2004).

7. Proportion of Current Range Where the Species is Negatively Impacting Biodiversity:Moderate significance
Comments: Present in most counties in the northeast US (NRCS 2004) and associated with economic loss in rangelands in California (NWCB 2003).

8. Proportion of Nation's Biogeographic Units Invaded:Moderate significance
Comments: Inferred from current distribtion (Kartesz 1999; NRCS 2004) and ecoregion boundaries (TNC 2001).

9. Diversity of Habitats or Ecological Systems Invaded in Nation:High significance
Comments: In grass- and woodlands, riverbanks and disturbed areas (Weber 2003). Prefers dry sandy or gravelly soils in pastures, pinyon-juniper woodlands, foothill forests, waste places, and on roadsides (NV Project WEEDS).

Subrank III. Trend in Distribution and Abundance: High/Medium

10. Current Trend in Total Range within Nation:Moderate significance
Comments: Occupied 3125 sq. miles in 50 years after introduction (1950) in California (NWCB 2003). Hypericum perforatum easily invades disturbed areas as well as some native plant habitats (see question # 14).

11. Proportion of Potential Range Currently Occupied:Low significance
Comments: Range includes areas of full sun to partial shade in USDA Zones 3 - 8 (Floridata 2004).

12. Long-distance Dispersal Potential within Nation:High significance
Comments: Water, soil and agricultural activities contribute to seed dispersal (Weber 2003). Also spread via cultivation for herbal and aesthetic benefits (NWCB 2003).

13. Local Range Expansion or Change in Abundance:High/Low significance
Comments: Hypericum perforatum can expand locally by clonal growth (NWCB 2003).

14. Inherent Ability to Invade Conservation Areas and Other Native Species Habitats:Moderate significance
Comments: Disturbances, such as fire, stimulate germination (Weber 2003). It can invade healthy rangelands (NWCB 2003).

15. Similar Habitats Invaded Elsewhere:Low significance
Comments: In grass- and woodlands, riverbanks and disturbed areas in the Caribbean, South America, Australia, New Zealand and North America (Weber 2003).

16. Reproductive Characteristics:High significance
Comments: Prolific seed production as well as vegetative spread by rhizomes (Weber 2003) and aboveground stems (NWCB 2003). Lateral roots may rot, creating autonomous clones (NWCB 2003). A seed bank may be viable from 6 - 10 years (NWCB 2003) or up to 30 years (Harris and Gill 1997 as cited in Buckley et al. 2003).

Subrank IV. General Management Difficulty: Medium

17. General Management Difficulty:Moderate significance
Comments: Hand pulling that includes root removal, repeated defoliation and herbicide treatments are all effective means of control (Weber 2003). Repeated treatments will be necessary, as bare ground resulting from removal of Hypericum perforatum results in a flush of H. perforatum seedlings (Weber 2003).

18. Minimum Time Commitment:Moderate significance
Comments: Repeated treatments will be necessary, as bare ground resulting from removal of Hypericum perforatum results in a flush of H. perforatum seedlings (Weber 2003). A seedbank may be vialbe for up to 10 years (NWCB 2003).

19. Impacts of Management on Native Species:Medium/Low significance
Comments: Inferred - removal methods may disturb soils allowing for other non-native species to invade.

20. Accessibility of Invaded Areas:High/Moderate significance
Comments: Cultivated herbal and ornamental (NWCB 2003).
Authors/Contributors
Help

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

References
Help
  • Buckley, Y.M., D.T. Briese, M. Rees. 2003. Demography and management of the invasive plant species Hypericum perforatum. I. Using multi-level mixed-effects models for characterizing growth, survival and fecundity in a long-term data set. Journal of Applied Ecology 40:481-493.

  • Floridata. 2004.10266 Rebel Circle, Tallahassee, Florida 32305. ONLINE www.floridata.com. Accessed, 2004.

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • Meades, S.J. & Hay, S.G; Brouillet, L. 2000. Annotated Checklist of Vascular Plants of Newfoundland and Labrador. Memorial University Botanical Gardens, St John's NF. 237pp.

  • Nevada Project WEEDS. No date. Weed wanted posters. University of Nevada Reno, Cooperative Extension. Available: http://www.ag.unr.edu/wsj/ipm/Wanted_posters/wpost.html. (Accessed 2004).

  • The Nature Conservancy. 2001. Map: TNC Ecoregions of the United States. Modification of Bailey Ecoregions. Online . Accessed May 2003.

  • USDA, ARS, National Genetic Resources Program. 2001. Germplasm Resources Information Network - (GRIN). [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.URL: http://www.ars-grin.gov/var/apache/cgi-bin/npgs/html/taxon.pl?6438. (Accessed 2004)

  • USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov) . National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • Washington State Noxious Weed Control Board (NWCB). 2003. Written Findings of the State Noxious Weed Control Board. Available: http://www.nwcb.wa.gov/weed_info/contents_common.html. (Accessed 2004).

  • Weber, E. 2003. Invasive plant species of the world: a reference guide to environmental weeds. CABI Publishing, Cambridge, Massachusetts. 548 pp.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of November 2016.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2017 NatureServe, 4600 N. Fairfax Dr., 7th Floor, Arlington Virginia 22203, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.