Hypericum perforatum

Hypericum perforatum, most often called St. John's wort, is a perennial herb in the Hypericaceae family. It has no hair on its stems or leaves, woody roots, bright yellow flowers with black glands along the petal edges, and leaves that look like they have tiny holes because of translucent glands. This species is the type for its genus and has a long history in folklore and traditional medicine. It likely started as a hybrid between Hypericum attenuatum and Hypericum maculatum in Siberia, and from there it has spread across the globe.

The plant is native across much of Europe, West and Central Asia, parts of Africa, and China, and has been widely introduced elsewhere. It grows best in well-drained, temperate spots like meadows, hillsides, and open woods with moderate rain and mild temperatures. It is tough, toxic, and invasive, reproducing both by seed and vegetatively. It supports certain specialized insect herbivores, can suffer from plant diseases, and causes ecological and agricultural problems in many regions.

Antidepressant effects

For centuries, people have used St. John's wort in traditional medicine, especially for wounds and depression. To prepare it, the oil from its glands can be extracted, or the above-ground parts can be dried and ground into a powder called herba hyperici. For mild to moderate depression, it shows antidepressant effects comparable to standard drugs but with fewer side effects, and it is approved for this use in the European Union. However, it can speed up the metabolism of various other medications, leading to interactions.

Description Hypericum perforatum is a perennial herb with smooth stems and leaves. Each plant has a slender, woody main root that can reach 0.6 to 1.5 meters deep, depending on conditions, along with many fine side roots and creeping rhizomes. The crown of the root is woody. The stems are erect, branched toward the top, and usually grow 0.3 to 1 meter tall.

Description

They are woody near the base, with a rusty-yellow to rosy color, two distinct edges, and bark that often peels near the bottom. Scars from fallen leaves give the stems a jointed look. Stems survive the winter and produce new growth with flower buds the following year; first-year stems do not flower. The leaves grow opposite each other on the stem without a stalk.