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.
Hypericum sect. Thornea is a small section of flowering plants in the genus Hypericum. It was formerly treated as a separate genus, Thornea. There are two species in the section, Hypericum calcicola and Hypericum matudae.
Triadenum fraseri known as bog St. John's wort, Fraser's St. John's wort, and Fraser's marsh St. John's wort, is a perennial flowering plant in the family Hypericaceae that is grows in wetlands of the northeastern and northcentral United States and lower Canada. It is named after John Fraser (1750–1811), a Scottish botanist and widely travelled plant collector.
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 ascyron, the great St. Johnswort or giant St. John's wort is a flowering plant in the family Hypericaceae.
Hypericum kalmianum, commonly called Kalm's St. Johns wort or Kalm's St. Johnswort, is a flowering plant in the St. John's wort family Hypericaceae. It is native to the Great Lakes region in the northern United States and southern Canada. Hypericum kalmianum was named after its discoverer, Swedish botanist Pehr Kalm (1715-1779).
Hypericum tenuifolium, known as Atlantic St. John's-wort and sandhill St. John's-wort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is native to the Southeastern United States.
Hypericum suffruticosum, known as pineland St. John's-wort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is native to the Southeastern United States.
Hypericum galioides, the bedstraw St. Johnswort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is endemic to the Southeastern United States.
Hypericum tetrapetalum, the fourpetal St. Johnswort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is found in the Southeastern United States and Cuba. It was first described by Jean-Baptiste Lamarck in 1797.
Hypericum myrtifolium, the myrtleleaf St. Johnswort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is endemic to the Southeastern United States. It was first described by Jean-Baptiste Lamarck in 1797.
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 erythreae, the Georgia St. John's-wort, sparse-leaved St. John's-wort, or grit St. Johnswort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is native to the southeastern United States in seepage bogs and roadside ditches. Its name grit St. Johnswort comes from its limited distribution, within the Altamaha Grit region of the Georgia coastal plain.
Hypericum fasciculatum, known as peelbark St. Johnswort or sandweed, is a species of flowering plant in the St. Johnswort family, Hypericaceae, native to the southeastern United States. It is found from eastern North Carolina, south to southern Florida, west to eastern Louisiana. Kew's Plants of the World Online database also notes that it occurs in Cuba, though Cuba is not listed in several other sources. It was first described in 1797 by Jean-Baptiste Lamarck.
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 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.
