Hostname: page-component-77c89778f8-gvh9x Total loading time: 0 Render date: 2024-07-22T09:32:03.671Z Has data issue: false hasContentIssue false
  • English
  • Français

Common St. Johnswort

Published online by Cambridge University Press:  12 June 2017

Larry W. Mitich
Larry W. Mitich*
Affiliation:
Sect. Plant Biology, Univ. California, Davis, CA 95616
Get access Rights & Permissions [Opens in a new window]

Extract

Worldwide, 10 genera and 400 species comprise the Hypericaceae, the St. Johnswort Family. The genus Hypericum, with 350 of these species (11), includes evergreen or deciduous shrubs, subshrubs, and herbaceous perennials. The hypericums have simple, opposite or whorled leaves and usually golden-yellow many-stamened flowers.

Common St. Johnswort (Hypericum perforatum L.) is a hairless perennial, reproducing by seeds and by runners from the base of the stem. It grows 20 to 100 cm tall, with spreading branches and small deep green glabrous oblong-ovate leaves, perforated by many translucent glandular dots. Branched clusters of golden yellow flowers with tiny black spots are produced from May to August (14).

Type
Intriguing World of Weeds
Information
Weed Technology , Volume 8 , Issue 3 , September 1994 , pp. 658 - 661
Copyright
Copyright © 1994 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Britton, N. L. and Brown, A. 1898. An Illustrated Flora of the Northern United States, Canada and the British Possessions. Volume 2. Charles Scribner's Sons, New York.Google Scholar
2. California Weed Conference. 1989. Principles of Weed Control in California, second edition. Thomson Publications, Fresno, CA. 511 p.Google Scholar
3. Campbell, M. H., Milne, B. R., Dellow, J. J., and Nicol, H. I. 1991. Effect of herbicides on St John's wort (Hypericum perforatum L.). Aust. J. Exp. Agric. 31(4):499–501.CrossRefGoogle Scholar
4. Culpeper, N. 1802. Culpeper's Herbal or The Complete English Family Physician, with additions by G. Gordon, A. Hogg and Co., London. 416 p.Google Scholar
5. Durant, Mary. 1976. Who Named the Daisy? Who Named the Rose? Dodd, Mead and Co., New York. 214 p.Google Scholar
6. Fields, P. G., Arnason, J. T., and Fulcher, R. G. 1990. The spectral properties of Hypericum perforatum leaves: the implications for its photactivated defenses. Can. J. Bot. 68(5): 1166–1170.CrossRefGoogle Scholar
7. George, A. 1942. Manual of Weeds. The Macmillan Co., New York. 593 p.Google Scholar
8. Gerard, J. 1928. Gerard's Herbal. Houghton Mifflin Co., Boston. 69 p.Google Scholar
9. Gordon, A. J., and Kluge, R. L. 1991. Biological control of St. John's wort, Hypericum perforatum, in South Africa. Agric., Ecosystems and Environ. 37 (1–3):77–90.CrossRefGoogle Scholar
10. Haughton, C. S. 1978. Green Immigrants. Harcourt Brace Jovanovich, Inc., New York. 450 p.Google Scholar
11. Hickman, J. C., ed. 1993. The Jepson Manual, Higher Plants of University. California Press, Berkeley. 1400 p.Google Scholar
12. Huffaker, C. B., and Kennett, C. E. 1959. A ten-year study of vegetational changes associated with biological control of Klamath weed. J. Range Manage. 12:69.CrossRefGoogle Scholar
13. Kingsbury, J. M. 1964. Poisonous Plants of the United States and Canada. Prentice-Hall, Inc., Englewood Cliffs, NJ. 626 p.Google Scholar
14. LeStrange, R. 1977. A History of Herbal Plants. Angus and Robertson, Publishers, London. 304 p.Google Scholar
15. Marsh, C. D. and Clawson, A. B. 1930. Toxic effect of St. Johnswort (Hypericum perforatum) on cattle and sheep. U.S. Dep. Agric., Tech. Bull. 202.Google Scholar
16. Moore, R. M., Williams, J. D., and Nicholls, A. O. 1989. Competition between Trifolium subterraneum L. and established seedlings of Hypericum perforatum L. var. angustifolium DC. Aust. J. Agric. Res. 40:1015–1025.CrossRefGoogle Scholar
17. Sampson, A. W., and Parker, K. W. 1930. St. Johnswort on range lands in California. Calif. Agr. Exp. Stn. Bull. 503.Google Scholar
18. Zimdahl, R. L. 1989. Words and Words. Iowa State University Press, Ames. 125 p.Google Scholar