When having a walk these last months in the nearby forest, I wondered which plant had these opposite leaves. I was sure having seen it earlier. When the yellow flowers appeared with their prominent stamens I found it was one of the species of Hypericum we had in the garden of a former house.
All members of the genus may be referred to as St. John's wort, their blooming period of the year. The genus name Hypericum is derived from the Greek words hyper (above) and eikon (picture), in reference to the tradition of hanging plants over religious icons in the home during St John's Day, to ward off evil.
There are more than 400 individual species in the genus varying from herbaceous annual or perennials.
The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and Polar Regions.
Some species are used as ornamental plants and have large, showy flowers. Many cultivars have gained the Royal Horticultural Society's Award of Garden Merit.
Common St. John's-wort (Hypericum perforatum) has long been used in herbalism. It was known to have medical properties in Classical Antiquity and was a standard component of Theriac. It is today grown commercially for use in herbalism and medicine. Two main compounds of interest have been studied in more detail: hyperforin and hypericin. As psychiatric medication, research data supports a noticeable effect in many cases of light and medium depression.
However it must be used with care because it can reduce the clinical efficacy of several drugs and have adverse effects on heart disorders.