The common name “St John’s wort” comes from its traditional flowering and harvesting on St John’s Day, 24 June. Perforate St John’s wort is a herbaceous perennial plant with creeping rhizomes. Its stems are erect, branched in the upper section, and can grow to 1 m high. It has opposite, stalk-less, narrow, oblong leaves that are 1–2 cm long, yellow-green in color, with scattered translucent dots of glandular tissue. The flowers are colored bright yellow with conspicuous black dots. The herb flowers between late spring and early to mid-summer. Hypericum perforatum is native to parts of Europe and Asia but has spread worldwide as a cosmopolitan invasive weed, including to temperate regions of India, China, Canada, Africa, and the United States. Except for Hypericin, this herb also contains Tannins and Flavonoids: Quercetin, quercitrin.