Renowned for its healing powers, common St. Johnswort is now found in most parts of the world. It has been used as a sedative, a treatment for malaria and depression, and a salve for wounds, burns, and insect bites. Its name is derived from a belief that its healing powers were enhanced by smoking it on the eve of St. John’s Day, June 24th. A shrubby perennial growing 2 feet tall, common St. Johnswort flowers from May through August, performing best in full sun, where it produces yellow blooms with five petals, five sepals, and many stamens. Its wide planting and habit of spreading by rhizomes has resulted in it becoming invasive in many areas where it has been classified as a noxious weed.