Hypericum perforatum var. angustifolium belongs to the family Clusiaceae. It is a perennial herb that is native to Europe. It is a variety of Common St. Johnswort and naturalized widely in Japan. This herb grows in waste places and roadsides, and can reach 60-90 cm in height. The leaves are oblong, less than 1.5 cm long, and have many gright dots. The yellow, about 2 cm across, flowers bloom from May to July.