Hypericum perforatum, commonly known as St John's wort, is a flowering plant in the family Hypericaceae and the type species of the genus Hypericum. It is a perennial that grows up to one meter tall, with many yellow flowers that have conspicuous black glands around their edges, long stamens, and three pistils. Probably a hybrid between close relatives H. attenuatum and H. maculatum that originated in Siberia, the species now has a cosmopolitan distribution. It is native to temperate regions across Eurasia and North Africa, and has been introduced to East Asia, Australia, New Zealand, and parts of North and South America. In many areas where it is not native, H. perforatum is considered a noxious weed. It densely covers open areas to the exclusion of native plants, and is poor grazing material. As such, methods for biocontrol have been introduced in an attempt to slow or reverse the spread of the species.
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 calycinum is a species of prostrate or low-growing shrub in the flowering plant family Hypericaceae. Widely cultivated for its large yellow flowers, its names as a garden plant include Rose-of-Sharon in Britain and Australia, and Aaron's beard, great St-John's wort, creeping St. John's wort and Jerusalem star. Grown in Mediterranean climates, widely spread in the Strandja Mountains along the Bulgarian and Turkish Black Sea coast.
Hypericum tetrapterum is a herbaceous perennial plant species in the flowering plant family Hypericaceae. Its common names include St. Peter's wort, Peterwort, square stemmed St. John's wort, and square stalked St. John's wort.
Hypericum canariense is a species of flowering plant in the family Hypericaceae known by the common name Canary Islands St. John's wort. It is the sole member of Hypericumsect. Webbia.
Hypericum maculatum, commonly known as imperforate St John's-wort, or spotted St. Johnswort, is a species of perennial herbaceous flowering plant in the family Hypericaceae. It is native to Europe and Western Asia where it grows in moist meadows.
Hypericum hirsutum is a species of flowering plant in the family Hypericaceae, commonly known as hairy St John's-wort. It is found in Western Europe.
Hypericum elodes, commonly known as marsh St John's-wort, is a species of flowering plant in the St. John's wort family Hypericaceae. It is native to Western Europe.
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 buckleyi, known as Blue Ride St. John's wort and Buckley's St. Johnswort, is a rare species of flowering plant in the family Hypericaceae found only in the Appalachian Mountains of the southeastern United States. The species is listed in the state of Georgia (S1), South Carolina (SX), and North Carolina (S3).
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 edisonianum, known as Arcadian St. John's wort, Edison's St. John's wort, and Edison ascyrum, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is endemic to Florida.
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 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 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 lancasteri, known as Lancaster's St. John's wort or as zhan e jin si tao in Chinese, is a species of flowering plant in the St. John's wort family Hypericaceae. The species has been awarded the Royal Horticultural Society's Award of Garden Merit.
Hypericum oblongifolium, known as Pendant St. John's wort, is a species of flowering plant in Hypericumsect. Ascyreia.
Hypericum frondosum, the cedarglade St. Johnswort or golden St. John's wort, is a species of flowering plant in the St. John's wort family, Hypericaceae. It is native to the central and southeastern United States in dry, rocky habitats.
Hypericum fissurale, known as cracked St. John's wort, is a flowering plant in the St. Johns's wort family (Hypericaceae) endemic to northeastern Turkey. It is considered critically endangered on the IUCN Red List due to its very limited distribution and declining population. It was first formally named by Jurij Nikolaewitch Woronow in 1912. It is a small perennial herb in the section Hypericum sect. Taeniocarpium, reaching around 22 cm (8.7 in) in height. Like most Hypericum species, it has flowers with five yellow petals and numerous stamens. Hypericum fissurale is closely related to Hypericum armenum.
