Common St John's wort (Hypericum perforatum) is a flowering plant species of the genus Hypericum. It is a medicinal herb with antidepressant properties and potential antibacterial and anti- inflammatory properties. Extracts of St John's wort can be used as a treatment for depression. Other names for St John's wort include Tipton's weed, rosin rose, goatweed, chase-devil, or Klamath weed.
Hypericum perforatum is a yellow-flowering, perennial herb indigenous to Europe. It has been introduced to many temperate areas of the world and grows wild in many meadows. The herb's common name comes from its traditional flowering and harvesting on St John's day, 24 June.
St John's wort is a perennial plant with extensive, creeping rhizomes. Its stems can grow to 1 m high. The leaves are yellow-green in color. Its flowers measure up to 2.5 cm across and are colored bright yellow with conspicuous black dots. When flower buds (not the flowers themselves) or seed pods are crushed, a purple liquid is produced. St John's wort is widely known as a herbal treatment for depression. In some countries, it is commonly prescribed for mild to moderate depression, especially in children and adolescents and has similar efficacy to standard antidepressants.