What is the definition or description of: st. john's wort?

See below: St john's wort is the plant species hypericum perforatum, and is also known as tipton's weed, rosin rose, goatweed, chase-devil, or klamath weed. St john's wort is widely known as an herbal treatment for depression. In some countries, such as germany, it is commonly prescribed for mild depression, especially in children and adolescents.