About Hypericum hirsutum L.
Hypericum hirsutum L., commonly called Hairy St John's wort, is a downy perennial plant that reaches a height of two to three feet. It has erect stems, with opposite pairs of untoothed, elongated oval leaves that bear translucent glandular dots. Its terminal inflorescences hold numerous pale yellow flowers. Each flower has five pointed sepals with stalked black dots along the margins; the five petals may also have black dots, and the many stamens are arranged in bundles. This species is very similar to common St John's wort (H. perforatum), but can be told apart by its downy stems and much longer leaves. Hypericum hirsutum occurs in temperate regions, with a native distribution spanning Europe and western Siberia. It is uncommon and localised in Finland, which lies at the northern edge of its European range. In Britain, it is widespread across most of the territory except for the far north and far west; in Ireland it is rare and localised, found at only two sites in Northern Ireland, with its Irish range centered around County Dublin. This perennial herb prefers free-draining, neutral to base-rich soils. It grows in open or partially shaded habitats, including rough ungrazed grassland, woodland clearings and rides, river banks, and road verges. In Britain, its altitudinal range extends from sea level up to 450 metres (1,480 ft) in Cumberland. At the extreme northern edge of its range, in south-western Finland, it grows in open, lime-rich sites and does not grow in shaded areas.