|St. John’s wort|
Hypericum perforatum is the most medicinally important species of the Hypericum genus, commonly known as St. John’s wort or Klamath weed. There are as many as 400 species in the genus, which belongs to the Clusiaceae family. Native to Europe, St. John’s wort is found throughout the world. It thrives in sunny fields, open woods, and gravelly roadsides.
Early colonists brought this plant to North America, and it has become naturalized in the eastern United States and California, as well as in Australia, New Zealand, eastern Asia, and South America. As of 2004, St. John’s wort is one of the most commonly used herbs in the United States, especially among women.
The entire plant, particularly its round black seeds, exudes a slight turpentine-like odor. The woody-branched root spreads from the base with runners that produce numerous stalks.