St. John's wort, or latin Hypericum perforatum, is a five-petalled,
yellow-flowered perennial weed common to the western United States, Europe and
Asia. The plant belongs to the
family Hypericaceae. It was named after St. John the
Baptist since the herb produced yellow flowers particularly abundant on June 24,
the day traditionally celebrated as his birthday. Other Christian authors
claimed that the red spots, symbolic of the blood of St. John, appeared on the
leaves on August 29, the anniversary of his beheading.
From the
time of the ancient Greeks down through the Middle ages, the plant was
considered to be imbued with magical powers to ward off evil spirits and protect
against various diseases. St. John's wort, applied topically or
systematically, has been used to treat bronchitis, burns, cancer, enuresis,
gastritis, hemorrhoids, hypothyroidism, insect bites, insomnia, kidney disease,
scabies, and wound healing. In the late nineteenth century, it fell into
disrepute like many plant drugs.
In the 1940s, St. John's
wort proved to be exceedingly troublesome to farmers in northern California and
southern Oregon because of it's photosensitizing properties that can be toxic to
cows and sheep and was given the name "Klamath weed". It was
estimated that over two million acres in northern California were overrun by the
"Klamath weed". After the use of herbicides failed, leaf beetles
from Australia, Chrysolina quadrigemina Rossi were introduced for their
voracious appetite for Hypericum. The beetles were so effective that the
number of St. John's wort was reduced to 1% of their original number.
Although the
therapeutic use of St. John's wort is approved in Germany for psychoautonomic
disturbances, depressive mood disorders, and anxiety, its popularity in the
U.S. didn't arrive until 1997. In June of that year, millions of Americans
diagnosed themselves as mildly to moderately depressed after a
feature on the plant by ABC's television news program 20/20. Product sales rose
dramatically following the national media attention. In 1998, St. John's
wort was the second best selling herbal medicinal product, selling over $140
million.
Photo courtesy of B.C. Ministry
of Agriculture, Food and Fisheries
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