Hypericum is a genus of flowering plants in the family Hypericaceae. The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and polar regions. Many Hypericum species are regarded as invasive species and noxious weeds. All members of the genus may be referred to as St. John's wort, and some are known as goatweed. The white or pink flowered marsh St. John's worts of North America and eastern Asia are generally accepted as belonging to the separate genus TriadenumRaf.
Hypericum androsaemum, the shrubby St. John's wort, is a flowering plant in the family Hypericaceae. Commonly called tutsan or sweet-amber, the species is cultivated as an ornamental plant because of its striking red-tinted foliage, bright yellow petals, and its clusters of fruit which are large compared to other members of Hypericum. As such, various cultivars of the species have been bred which amplify its desirable characteristics. These include cultivars like 'Albury Purple' and 'Golden Tutsan' which have leaves with more pronounced purple and golden coloring, respectively.
Hypericum mutilum is a species of St. John's wort known by the common name dwarf St. John's wort. It is native to parts of North America and is present in other parts as an introduced species. It is an annual or perennial herb taking a multibranched erect form up to about 60 centimeters tall. The oval green leaves are one or two centimeters long and are covered in tiny glands. The inflorescence is a compound cyme of tiny flowers. H. mutilum subsp. mutilum and subsp. boreale have a diploid number of 16, and H. mutilum subsp. boreale can have a diploid number of 18.
Hypericum olympicum, commonly known as the Mount Olympus St. John's wort, is a species of flowering plant in the family Hypericaceae found in the Balkans and Turkey and introduced to western Europe. It has been widely cultivated for centuries because of its large, showy flowers, which are far larger than those of most other species in Hypericum.
Hypericum aegypticum is a species of flowering plant of the St. John's wort family (Hypericaceae) which is native to the Eastern Mediterranean. It was described by Carl Linnaeus in the second volume of his Species Plantarum in 1753, who named it after Egypt despite it not being distributed there. The plant is commonly known as shrubby St. John's wort or Egyptian St. John's wort in English. Like other members of section Adenotrias, it is found among limestone rocks in coastal areas. While it has been evaluated as threatened on the island of Malta, the species has no legal protections.
Hypericum annulatum is a species of flowering plant in the family Hypericaceae. It is a perennial herb of varying heights which grows upright, with more than a hundred flowers of a golden yellow color. First described in 1827, the species has a wide distribution from Eastern Europe to East Africa, and its appearance can vary greatly based on its geographic location. It has been used in Bulgarian folk medicine, and has more recently been investigated for its effectiveness in slowing the growth of or killing certain types of human cancer.
Hypericum cuisinii is a perennial herb in the genus Hypericum, in the section Adenosepalum. The herb has pale yellow flowers and occurs in Greece and Turkey.
Hypericum undulatum, the wavy St Johns Wort, is a herbaceous perennial flowering plant native to western Europe and northern Africa. The specific name undulatum is Latin, meaning "wavy" or "undulated", referring, just as the common name, to the wavy leaf margins of the herb. The plant has a diploid number of 16 or 32.
Hypericum sect. Adenosepalum is one of 36 sections in the genus Hypericum. Its type species is Hypericum montanum.
Hypericum majus, the greater Canadian St. John's wort, is a perennial herb native to North America. The specific epithet majus means "larger". The plant has a diploid number of 16.
Hypericum sampsonii is a species of flowering plant in the St. John's wort family, Hypericaceae. It occurs in China, Taiwan, Japan, Myanmar, and Vietnam. It is one of two species of Hypericum in the section Hypericum sect. Sampsonia.
Hypericum sechmenii, commonly called seçmen kantaronu in Turkish which means Seçmen's St. John's wort in English, is a rare species of flowering plant of the St. John's wort family (Hypericaceae) that is found only in the Eskişehir Province of central Turkey. It was described by Turkish botanists Atila Ocak and Onur Koyuncu who named the species in honor of Özcan Seçmen, a fellow Turkish botanist. Found in the crevices of exposed limestone, it is a perennial herb which grows in clusters of stems 3–6 centimetres tall and blooms June to July with bright yellow five-petalled flowers. Formally described in 2009, the species was first collected in 2006 and has since been found in only two localities with an estimated population of less than 250.
Hypericum formosissimum is a species of flowering plant in the family Hypericaceae, section Adenosepalum, in the Hypericum huber-morathii group.
Hypericum huber-morathii is a flowering plant in the family Hypericaceae, section Adenosepalum, and the type species of the Hypericum huber-morathii group.
Hypericum aucheri, also known as Koramanotu in Turkish, is a herbaceous perennial flowering plant in the St. John's wort family Hypericaceae.
Hypericum coris, the heath-leaved St. John's wort, also called yellow coris, is a species of flowering plant in the family Hypericaceae, and is the type species of sect. Coridium. It is a low shrub, and it is found in Switzerland and northwestern Italy. The species has been a popular garden plant since the 18th century, valued for its long flowering period and for how well it adapts to cultivation.
Hypericum heterophyllum is a flowering plant in the Hypericaceae family and is the only species in Hypericum sect. Heterophylla.
Hypericum elodeoides, commonly called the Himalayan St. John's Wort, is a species of flowering plant of the St. John's wort family (Hypericaceae).
Hypericum orientale, the Ptarmic-leafed St. John's wort or Eastern St. John's wort, is a flowering plant in the family Hypericaceae. It is distributed across northern Turkey, Georgia, the Caucasus, and Dagestan. The species can be found on stony sloped amidst volcanic rocks in the mountains and in light woodlands at elevations of up to 2,300 m (7,500 ft). It flowers from May to June and July to August. The plant has small, bright yellow flowers and grows across the ground in a creeping pattern. It prefers full sun and is ideal for rock gardens, and is hardy down to -30° F.
