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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
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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 

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References

Literature Cited

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