Hypericum is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of about 400 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Hypericaceae

Hypericaceae

Hypericaceae is a plant family in the order Malpighiales. Molecular data supports its monophyly. Some systematists treat it as a subfamily of the Clusiaceae. When it is accepted as a distinct family, it contains the following genera:* Cratoxylum Blume...

 (formerly often considered a subfamily of Clusiaceae

Clusiaceae

The Clusiaceae or Guttiferae Juss. is a family of plants formerly including about 37 genera and 1610 species of trees and shrubs, often with milky sap and fruits or capsules for seeds. It is primarily tropical...

).

The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts

Déserts

Déserts is a piece by Edgard Varèse for brass , percussion , piano, and tape. Percussion instruments are exploited for their resonant potential, rather than used solely as accompaniment...

 and polar region

Polar region

Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The North Pole and South Pole being the centers, these regions are dominated by the polar ice caps, resting respectively on the Arctic Ocean and the continent of Antarctica...

s. All members of the genus may be referred to as St. John's wort, though they are also commonly just called hypericum, and some are known as tutsan. The marsh St. John's-worts are nowadays separated into the genus Triadenum

Triadenum

Triadenum is a genus of flowering plants in the family Hypericaceae. The genus is characterized by opposite, blunt-tipped leaves and pink flowers with 9 stamens....

.

St. John's-worts vary from annual

Annual plant

An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

 or perennial herbaceous

Herbaceous

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

 herb

Herb

Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...

s 5–10 cm tall to shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

s and small tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s up to 12 m tall. The leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are opposite, simple oval, 1–8 cm long, either deciduous

Deciduous

Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 or evergreen. The flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s vary from pale to dark yellow, and from 0.5–6 cm in diameter, with five (rarely four) petals. The fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 is usually a dry capsule which splits to release the numerous small seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s; in some species it is fleshy and berry

Berry

The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....

-like.

Uses of Hypericum

Some species are used as ornamental plant

Ornamental plant

Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...

s and have large, showy flowers. Numerous hybrids and cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s have been developed for use in horticulture

Horticulture

Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...

, such as Hypericum × moserianum (H. calycinum

Hypericum calycinum

Hypericum calycinum is a prostrate or low-growing shrub species of the genus Hypericum . 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, and Jerusalem star.Grown in Mediterranean...

× H. patulum) and Hypericum calycinum cv. 'Hidcote'.

St. John's-worts can occur as nuisance weed

Weed

A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...

s in farmland and gardens. On pasture

Pasture

Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...

s, some can be more than a nuisance, causing debilitating photosensitivity

Photosensitivity

Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light.- Human medicine :Sensitivity of the skin to a light source can take various forms. People with particular skin types are more sensitive to sunburn...

 and sometimes abortion

Abortion

Abortion is defined as the termination of pregnancy by the removal or expulsion from the uterus of a fetus or embryo prior to viability. An abortion can occur spontaneously, in which case it is usually called a miscarriage, or it can be purposely induced...

 in livestock

Livestock

Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

. The beetle

Beetle

Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

s Chrysolina quadrigemina, Chrysolina hyperici and the St. John's-wort Root Borer (Agrilus hyperici) like to feed on Common St. John's-wort (H. perforatum) and have been used for biocontrol

BioControl

BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...

 where the plant has become an invasive weed.

Hypericum species are the only known food plants of the caterpillar

Caterpillar

Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...

 of the Treble-bar

Treble-bar

The Treble-bar or St. John's Wort Inchworm is a moth of the family Geometridae. It is found throughout the Palearctic region and the Near East....

, a species of moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

. Other Lepidoptera

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

 species whose larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e sometimes feed on Hypericum include Common Emerald

Common Emerald

The Common Emerald is a moth of the family Geometridae. The species is found throughout the Nearctic and Palearctic regions and the Near East. In the British Isles it is not found in Scotland but is a common species elsewhere...

, The Engrailed

Engrailed

The Engrailed and Small Engrailed are moths of the family Geometridae. They are distributed across most of Europe. There is an on-going debate as to whether they make up one species, or whether E. crepuscularia actually refers only to the Small Engrailed, with the Engrailed proper being separable...

 (recorded on Imperforate St. John's-wort, H. maculatum), Grey Pug

Grey Pug

The Grey Pug is a moth of the family Geometridae. It is found throughout the Palearctic region and the Near East.The forewings of this species are grey marked with pale fascia and radial lines which give it a mottled appearance. The hindwings are much paler and plainer. Melanism is quite common in...

 and Setaceous Hebrew Character

Setaceous Hebrew Character

The Setaceous Hebrew Character is a moth of the family Noctuidae. It is found in the Palearctic ecozone. It is a common species throughout Europe. It is also found in North America, from coast to coast across Canada and the northern United States to western Alaska. It occurs in the Rocky Mountains...

.

Medical properties

Common St. John's-wort (H. perforatum) has long been used in herbalism

Herbalism

Herbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, herblore, and phytotherapy...

. It was known to have medical properties in Classical Antiquity

Classical antiquity

Classical antiquity is a broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world...

 and was a standard component of theriac

Theriac

Theriac or theriaca was a medical concoction originally formulated by the Greeks in the 1st century AD and became popular throughout the ancient world as far away as China and India via the trading links of the Silk Route...

s, from the Mithridate

Mithridate

Mithridate, also known as mithridatium, mithridatum, or mithridaticum, is a semi-mythical remedy with as many as 65 ingredients, used as an antidote for poisoning, and said to be created by Mithradates VI Eupator of Pontus in the 1st century BC...

 of Aulus Cornelius Celsus

Aulus Cornelius Celsus

Aulus Cornelius Celsus was a Roman encyclopedist, known for his extant medical work, De Medicina, which is believed to be the only surviving section of a much larger encyclopedia. The De Medicina is a primary source on diet, pharmacy, surgery and related fields, and it is one of the best sources...

' De Medicina (ca. 30 CE

Common Era

Common Era ,abbreviated as CE, is an alternative designation for the calendar era originally introduced by Dionysius Exiguus in the 6th century, traditionally identified with Anno Domini .Dates before the year 1 CE are indicated by the usage of BCE, short for Before the Common Era Common Era...

) to the Venice treacle of d'Amsterdammer Apotheek in 1686. Folk usages included oily extract ("St. John's oil") and Hypericum snaps

Snaps

Snaps is a Danish and Swedish word for a small shot of a strong alcoholic beverage taken during the course of a meal. A ritual that is associated with drinking snaps is a tradition in Scandinavia, especially in Denmark and Sweden, where it is very common to drink snaps at holidays such as...

.

H. perforatum is the most potent species and it is today grown commercially for use in herbalism and medicine

Medicine

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

; other St. John's-worts possess interesting properties and chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

s but are not well researched. As these secondary compounds appear to be related to deterring herbivores, they are present in varying and unpredictable quantities: still, a number of high-yield cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s have been developed.

Two main compounds of interest have been studied in more detail: hyperforin

Hyperforin

Hyperforin is a phytochemical produced by some of the members of the plant genus Hypericum, notably Hypericum perforatum .- Occurrence :...

 and hypericin

Hypericin

Hypericin is a naphthodianthrone, a red-colored anthraquinone-derivative, which, together with hyperforin, is one of the principal active constituents of Hypericum . Hypericin is believed to act as an antibiotic and non-specific kinase inhibitor...

. However, the pharmacology

Pharmacology

Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...

 of H. perforatum is not resolved, and at least its antidepressant

Antidepressant

An antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. According to Gelder, Mayou &*Geddes people with a depressive illness will experience a therapeutic effect to their mood;...

 properties are caused by a wide range of factors interacting. As psychiatric medication

Psychiatric medication

A psychiatric medication is a licensed psychoactive drug taken to exert an effect on the mental state and used to treat mental disorders. Usually prescribed in psychiatric settings, these medications are typically made of synthetic chemical compounds, although some are naturally occurring, or at...

, it is usually taken as pills, or as tea. Few standardised preparations are available, and research has mainly studied alcoholic extracts and isolated compounds. What research data exists supports a noticeable effect in many cases of light and medium depression

Clinical depression

Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...

, but no significant improvement of severe depression and OCD.

Another common use of H. perforatum is as an oily extract: the ruby

Ruby

A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum . The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires...

-red oil appears to be strongly antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

, assisting healing of wounds, first-degree burns and concussions. Both hypericin and hyperforin are reported to have antibiotic properties. Justifying this view with the then-current doctrine of signatures

Doctrine of signatures

The doctrine of signatures is a philosophy shared by herbalists from the time of Dioscurides and Galen. This doctrine states that herbs that resemble various parts of the body can be used to treat ailments of that part of the body. Examples include the plants liverwort; snakeroot, an antidote for...

, herbalist

Herbalist

An herbalist is:#A person whose life is dedicated to the economic or medicinal uses of plants.#One skilled in the harvesting and collection of medicinal plants ....

 William Coles (1626–1662) wrote in the 17th century that

"The little holes whereof the leaves of Saint Johns wort are full, doe resemble all the pores of the skin and therefore it is profitable for all hurts and wounds that can happen thereunto."

There is evidence that St. John's-worts can act as abortifacient

Abortifacient

An abortifacient is a substance that induces abortion. Abortifacients for animals that have mated undesirably are known as mismating shots....

s since interference with the Combined oral contraceptive pill has occurred. Complications have also been observed in other human patients: high-dosage H. perforatum interacts with a wide range of medications due to activation of the Pregnane X receptor

Pregnane X receptor

In the field of molecular biology, the pregnane X receptor , also known as the steroid and xenobiotic sensing nuclear receptor or nuclear receptor subfamily 1, group I, member 2 is a protein that in humans is encoded by the NR1I2 gene.PXR is a nuclear receptor whose primary function is to sense...

 detoxification pathway, as well as causing photosensitivity

Photosensitivity

Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light.- Human medicine :Sensitivity of the skin to a light source can take various forms. People with particular skin types are more sensitive to sunburn...

. It is strongly recommended not to take St. John's-wort during pregnancy or when tanning, and it has caused a few deaths in patients undergoing anti-HIV/AIDS and cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

 therapy. Extremely high doses (rarely reached with OTC

Over-the-counter drug

Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...

 preparations) are hepatotoxic.
Hypericum extract, by inducing both the CYP3A4

CYP3A4

Cytochrome P450 3A4 , a member of the cytochrome P450 mixed-function oxidase system, is one of the most important enzymes involved in the metabolism of xenobiotics in the body. CYP3A4 is involved in the oxidation of the largest range of substrates of all the CYPs. As a result, CYP3A4 is present in...

 and the P-glycoprotein

P-glycoprotein

P-glycoprotein 1 also known as multidrug resistance protein 1 or ATP-binding cassette sub-family B member 1 or cluster of differentiation 243 is a glycoprotein that in humans is encoded by the ABCB1 gene...

 (P-gp), can reduce the plasma concentrations of different antineoplastic agents such as imatinib

Imatinib

Imatinib is a drug used to treat certain types of cancer. It is currently marketed by Novartis as Gleevec or Glivec as its mesylate salt, imatinib mesilate . It is used in treating chronic myelogenous leukemia , gastrointestinal stromal tumors and some other diseases...

, irinotecan

Irinotecan

Irinotecan is a drug used for the treatment of cancer.Irinotecan prevents DNA from unwinding by inhibition of topoisomerase 1. In chemical terms, it is a semisynthetic analogue of the natural alkaloid camptothecin....

 and docetaxel, thus reducing the clinical efficacy of these drugs.

Hypericum perforatum may be capable of reducing the physical signs of opiate withdrawal.

Hypericum is a common treatment in homeopathy

Homeopathy

Homeopathy is a form of alternative medicine in which practitioners claim to treat patients using highly diluted preparations that are believed to cause healthy people to exhibit symptoms that are similar to those exhibited by the patient...

, used for the healing of deep wounds or as a relief from depression.

Selected species

• Hypericum acmosepalum
• Hypericum acostanum
  Hypericum acostanum
  Hypericum acostanum is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.Its natural habitats are subtropical or tropical dry shrubland and subtropical or tropical high-altitude shrubland.-Sources:...
  
  
• Hypericum addingtonii
• Hypericum adenotrichum
• Hypericum aegypticum
• Hypericum anagalloides
  Hypericum anagalloides
  Hypericum anagalloides is a species of St. John's wort known by the common names Creeping St. John's-wort, tinker's penny and Bog St. John's-wort....
  
  – Creeping St. John's-wort, Bog St. John's-wort, Tinker's-penny
• Hypericum androsaemum
  Hypericum androsaemum
  Hypericum androsaemum, commonly known as tutsan, is a plant in the genus Hypericum native to open woods and hillsides in Eurasia. It is a perennial shrub reaching up to 1.5 m in height.-Common name:...
  
  – Tutsan
• Hypericum annulatum
• Hypericum aphyllum
• Hypericum ascyron
• Hypericum asplundii
  Hypericum asplundii
  Hypericum asplundii is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.-Source:* Nicolalde, F. & Pitman, N. 2004. . Downloaded on 20 July 2007....
  
  
• Hypericum athoum
• Hypericum atomarium
• Hypericum augustinii
• Hypericum balearicum
  Hypericum balearicum
  Hypericum balearicum is a plant in the genus Hypericum native to Spain's Balearic Islands. It is a small, evergreen shrub up to 1.5 m in height, with dark green, leathery leaves covered with warty glands, and bright yellow flowers ....
  
  
• Hypericum balfourii
  Hypericum balfourii
  Hypericum balfourii is a species of flowering plant in the Hypericaceae family.It is found only in Yemen.Its natural habitats are subtropical or tropical dry shrubland and rocky areas.-Source:* Miller, A. 2004. . Downloaded on 20 July 2007....
  
  
• Hypericum barbatum
• Hypericum beanii
• Hypericum bellum
• Hypericum boreale – Northern St. John's-wort
• Hypericum buckleii – Blue Ridge St. John's-wort
• Hypericum bupleuroides
• Hypericum calycinum
  Hypericum calycinum
  Hypericum calycinum is a prostrate or low-growing shrub species of the genus Hypericum . 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, and Jerusalem star.Grown in Mediterranean...
  
  – Great St. John's-wort, Jerusalem Star, "Rose of Sharon
  Rose of Sharon
  Rose of Sharon is a common name that applies to several different species of flowering plants that are highly valued throughout the world. The name's colloquial application has been used as an example of the lack of precision of common names, which potentially causes confusion...
  
  ", "Aaron's Beard"
  • Hypericum calycinum cv. 'Hidcote'
• Hypericum canadense L. – Canadian St. John's-wort, Irish St. John's-wort
• Hypericum canariense
  Hypericum canariense
  Hypericum canariense is a species of St. John's wort known by the common name Canary Islands St. John's wort.-Distribution:It is endemic to the Canary Islands, where it grows in the coastal scrub and moist forested slopes of the five westernmost islands...
  
  – Canary Islands St. John's-wort
• Hypericum capitatum
• Hypericum cerastoides
• Hypericum choisianum
• Hypericum cistifolium
• Hypericum concinnum
  Hypericum concinnum
  Hypericum concinnum is a species of wildflower known by the common name gold-wire or goldwire. It is quite similar in appearance to St. John's wort, which is in the same genus. It is a short perennial plant bearing bunches of bright yellow flowers on its stems. The flower has long petals which fold...
  
  – Goldwire
• Hypericum confertum
• Hypericum cordifolium
• Hypericum coris
• Hypericum crenulatum
• Hypericum crux-andreae
• Hypericum cumulicola
  Hypericum cumulicola
  Hypericum cumulicola is a rare species of flowering plant in the St. John's wort genus known by the common name highlands scrub St. John's wort, or highlands scrub hypericum. It is endemic to Florida, where it is threatened by habitat loss and degradation...
  
  – Highlands Scrub Hypericum
• Hypericum curvisepalum
• Hypericum delphicum
• Hypericum densiflorum – Glade St. John's-wort, Dense St.John's-wort
• Hypericum denticulatum Walt. – Coppery St. John's-wort
• Hypericum dissimulatum – Disguised St. John's-wort
• Hypericum dyeri
• Hypericum eastwoodianum
• Hypericum elegans
• Hypericum ellipticum
• Hypericum elodes
  Hypericum elodes
  Hypericum elodes is a flowering plant in the genus Hypericum, commonly known as marsh St John's wort. It is native to Western Europe.-Description:...
  
  – Marsh Hypericum
• Hypericum elongatum
• Hypericum empetrifolium
• Hypericum erectum
• Hypericum ericoides
• Hypericum fasciculatum
• Hypericum fieriense
  Hypericum fieriense
  Hypericum fieriense is a species of flowering plant in the Hypericaceae family.It is found only in Yemen.Its natural habitats are subtropical or tropical dry shrubland and rocky areas....
  
  
• Hypericum foliosum
• Hypericum formosum – Western St. John's-wort
• Hypericum forrestii
• Hypericum fragile
• Hypericum frondosum – Cedarglade St. Johns-wort
• Hypericum galioides
• Hypericum gentianoides (L.) BSP. – Orange-grass St. John's-wort, Pinweed
• Hypericum glandulosum
• Hypericum gnidiifolium
  Hypericum gnidiifolium
  Hypericum gnidiifolium is a species of flowering plant in the Hypericaceae family.It is found only in Ethiopia.-Source:* World Conservation Monitoring Centre 1998. . Downloaded on 20 July 2007....
  
  
• Hypericum gramineum
• Hypericum grandifolium
  Hypericum grandifolium
  Hypericum grandifolium Choisy is a plant in the family Hypericaceae endemic to Madeira and the Canary Islands. It is a evergreen shrub up to 1.8 m in height, with dark green, leathery leaves covered with warty glands, and bright yellow flowers up to 4.5 cm broad...
  
  
• Hypericum graveolens
• Hypericum hartwegii
  Hypericum hartwegii
  Hypericum hartwegii is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.-Source:* Nicolalde, F. & Pitman, N. 2004. . Downloaded on 20 July 2007....
  
  
• Hypericum henryi
• Hypericum hircinum – Stinking Tutsan
• Hypericum hirsutum
  Hypericum hirsutum
  Hypericum hirsutum is a flowering plant in the genus Hypericum commonly known as hairy St John's wort. It is found in Western Europe.-Description:...
  
  L. – Hairy St. John's-wort
• Hypericum hookerianum
• Hypericum humifusum
  Hypericum humifusum
  Hypericum humifusum is a prostrate flowering plant in the genus Hypericum commonly known as trailing St John's wort. It is found in Western Europe.-Description:...
  
  L. – Trailing St. John's-wort
• Hypericum hypericoides
• Hypericum hyssopifolium
• Hypericum × inodorum
• Hypericum japonicum
• Hypericum kalmianum – Kalm's St. John's-wort
• Hypericum kamtschaticum Ledeb.
• Hypericum kelleri
• Hypericum kotschyanum
• Hypericum kouytchense
• Hypericum lagarocladum
• Hypericum lancasteri – Lancaster's St. John's-wort
• Hypericum lanceolatum
• Hypericum lanuginosum
• Hypericum leschenaultii
• Hypericum linariifolium – Toadflax-leaved St. John's-wort
• Hypericum linarioides
• Hypericum llanganaticum
  Hypericum llanganaticum
  Hypericum llanganaticum is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.Its natural habitats are subtropical or tropical moist montanes and subtropical or tropical high-altitude grassland.-References:...
  
  
• Hypericum lobbii
• Hypericum lobocarpum
• Hypericum maclarenii
• Hypericum maculatum
  Hypericum maculatum
  Hypericum maculatum Crantz is a species of perennial herbaceous plants in the genus Hypericum, native to Europe and Western Asia and occurring in meadows....
  
  – Imperforate St. John's-wort
• Hypericum maguirei
  Hypericum maguirei
  Hypericum maguirei is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.Its natural habitat is subtropical or tropical high-altitude grassland.-Sources:...
  
  
• Hypericum majus – Larger Canadian St. John's-wort
• Hypericum matangense
  Hypericum matangense
  Hypericum matangense is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.Its natural habitat is subtropical or tropical high-altitude grassland.-Sources:...
  
  
• Hypericum monogynum
• Hypericum montanum
  Hypericum montanum
  Hypericum montanum is a plant species in the genus Hypericum....
  
  L. – Pale St. John's-wort
• Hypericum montbretii
• Hypericum × moserianum
• Hypericum mutilum
  Hypericum mutilum
  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...
  
  L. – Dwarf St. John's-wort
• Hypericum myricariifolium Hieron.
• Hypericum nanum
• Hypericum nudiflorum
• Hypericum nummularium – Round-leaved St. John's-wort
• Hypericum oblongifolium
• Hypericum olympicum
• Hypericum orientale
• Hypericum origanifolium
• Hypericum pallens
• Hypericum patulum Thunb
• Hypericum peninsulare
• Hypericum perfoliatum
• Hypericum perforatum – Common St. John's-wort, Perforate St John's-wort, Tipton's Weed, Klamath Weed
  • Hypericum perforatum cv. 'Anthos'
• Hypericum prietoi
  Hypericum prietoi
  Hypericum prietoi is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.Its natural habitat is subtropical or tropical high-altitude grassland.-Source:...
  
  
• Hypericum prolificum – Shrubby St. John's-wort
• Hypericum pseudohenryi – Irish Tutsan
• Hypericum pulchrum
  Hypericum pulchrum
  Hypericum pulchrum is a flowering plant in the genus Hypericum, commonly known as slender St John's wort. It is native to Western Europe.-Description:...
  
  – Slender St. John's-wort
• Hypericum punctatum Lam. – Spotted St. John's-wort
• Hypericum quitense
  Hypericum quitense
  Hypericum quitense is a species of flowering plant in the Hypericaceae family.It is found only in Ecuador.Its natural habitats are subtropical or tropical dry shrubland and coral reefs.-References:...
  
  
• Hypericum reflexum
• Hypericum reptans
• Hypericum reductum
• Hypericum revolutum Vahl
• Hypericum richeri
• Hypericum roeperanum Schimp. ex A. Rich.
• Hypericum rumeliacum
• Hypericum sampsonii
• Hypericum scopulorum
  Hypericum scopulorum
  Hypericum scopulorum is a species of flowering plant in the Hypericaceae family.It is found only in Yemen.Its natural habitats are subtropical or tropical dry shrubland and rocky areas.-References:* Miller, A. 2004. . Downloaded on 20 July 2007....
  
  
• Hypericum scouleri – Western St. John's-wort
• Hypericum setosum
• Hypericum socotranum
  Hypericum socotranum
  Hypericum socotranum is a species of flowering plant in the Hypericaceae family.It is found only in Yemen.Its natural habitats are subtropical or tropical dry forests and rocky areas.-References:* Miller, A. 2004. . Downloaded on 20 July 2007....
  
  
• Hypericum sphaerocarpum – Roundfruit St. John's-wort
• Hypericum spruneri
• Hypericum stellatum
• Hypericum subsessile
• Hypericum tenuicaule
• Hypericum tetrapterum
  Hypericum tetrapterum
  Hypericum tetrapterum is a species in the genus Hypericum, in the family Hypericaceae. Its common names include St. Peter's Wort, Peterwort, Square Stemmed St. John's Wort, and Square Stalked St. John's Wort....
  
  – Square-stalked St. John's-wort, Square-stemmed St. John's-wort, St. Peter's-wort, Peterwort
• Hypericum tomentosum
• Hypericum tortuosum
  Hypericum tortuosum
  Hypericum tortuosum is a species of flowering plant in the Hypericaceae family.It is found only in Yemen.Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland.-References:...
  
  
• Hypericum trichocaulon
• Hypericum triquetrifolium
  Hypericum triquetrifolium
  Hypericum triquetrifolium is a species of plant of the family Hypericaceae.-External links:* ]]...
  
  – Curled-leaved St. John's-wort
• Hypericum undulatum – Wavy St. John's-wort
• Hypericum uralum
• Hypericum vacciniifolium
• Hypericum wilsonii
• Hypericum xylosteifolium – Turkish Tutsan
• Hypericum yakusimense

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