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.
Hypericaceae is a plant family in the order Malpighiales, comprising six to nine genera and up to 700 species, and commonly known as the St. John's wort family. Members are found throughout the world apart from extremely cold or dry habitats. Hypericum and Triadenum occur in temperate regions but other genera are mostly tropical.
Triadenum, known as marsh St. John's worts, is a small genus of flowering plants in the family Hypericaceae. The genus is characterized by opposite, blunt-tipped leaves and pink flowers with 9 stamens. They are distributed in North America and eastern Asia.
Hypericum balearicum is a species of flowering plant in the family Hypericaceae, native to Spain's Balearic Islands. It is the only species in the section Psorophytum.
Hypericum cerastioides is a species of perennial flowering plant in the St. John's wort family, Hypericaceae. It is the only species in the section Hypericum sect. Campylopus.
Hypericum japonicum, known as matted St. John's-wort, is an annual herbaceous flowering plant in the St. John's wort family Hypericaceae, in Hypericum sect. Trigynobrathys.
Hypericum assamicum is a species of flowering plant in the St. John's wort family, Hypericaceae. It is endemic to India. Hypericum assamicum is one of two species of Hypericum in the section Hypericum sect. Sampsonia.
Hypericum huber-morathii is a flowering plant in the family Hypericaceae, section Adenosepalum, and the type species of the Hypericum huber-morathii group.
Hypericum virginicum, the marsh St. Johns-wort or Virginia marsh St. Johnswort, is a species of flowering plant in the family Hypericaceae. It is native to the central and eastern United States and eastern Canada.
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 antiquum is an extinct species of the genus Hypericum that was present during the Eocene epoch. The species' fossils are the oldest collected of Hypericum, and it is believed that the species is the common ancestor of the tribe Hypericeae. Fossil seeds have been found in Russia, and the predicted paleoregion of the species stretched across Eurasia. It is theorized that one factor leading to the species' extinction is a global cooling at the end of the Eocene that removed much of its habitat.
Hypericum tubulosum, the lesser marsh St. Johnswort or southern marsh St. John's-wort, is a species of flowering plant in the family Hypericaceae. Formerly classified as synonym Triadenum tubulosum, the species is found across the Southern United States and Midwest. It grows in wetlands such as bogs and floodplains.
Hypericum minutum is a flowering plant in the genus Hypericum, sect. Adenosepalum.
Hypericum holyi is an extinct species of the genus Hypericum that was present from the Lower Miocene to the Upper Miocene. Fossil seeds of the species have been found in Central Europe in general and Central Jutland, Denmark, in particular.
Hypericum confertum is a species of flowering plant of the St. John's Wort family (Hypericaceae) which is native from Turkey to Lebanon and on the island of Cyprus.
Hypericum septestum is an extinct species of the genus Hypericum that was present during the Oligocene and Miocene epochs. Its holotype is a fossil seed from the Lower Oligocene that was collected in Western Siberia in 1965, and fossils of the species has also been found in other parts of Russia and in the Czech Republic.
Hypericum tertiaerum is an extinct species of the genus Hypericum. Seeds of H. tertiaerum have been found in Central and Eastern Europe and Siberia, and date from the Lower to Upper Miocene and the Pliocene. While it has sufficient identifying characteristics to place it within Hypericum, there is not enough surviving detail to assign it to any subdivisions within the genus. However, it has been determined that the seeds of H. japonicum, H. virginicum, and H. tubulosum closely resemble those of H. tertiaerum.
Hypericum miocenicum is an extinct species of the genus Hypericum. Seeds of the species have been recorded from the Late Oligocene in Germany, the Late Miocene in Poland (Poznan), and the Pliocene in Germany (Thuringia). It differs from H. septestum, a more frequently found Hypericum paleospecies, by its thinner foveole walls and the shape of its surface cells, which are more rectangular.
Hypericum danicum is an extinct species of flowering plant in the family Hypericaceae. The species is known from a fossil seed found among other Hypericum seeds in Italy, and is dated to the Pliocene. It has also been recorded several times from the Søby region of Denmark, also by discovered fossil seeds.
