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

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s. ''

Hypericum ''Hypericum'' is a genus of flowering plants in the family Hypericaceae (formerly considered a subfamily of Clusiaceae). The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and polar regions. Many ''Hype ...

'' and ''

Triadenum ''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 a ...

'' occur in temperate regions but other genera are mostly tropical.

Characteristics

Members of this family are annual or

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

herbs, subshrubs or shrubs. The leaves are simple and entire, in opposite pairs; they are sometimes dotted with black or translucent glandular spots. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

consists of a branched, flat-topped cluster, each flower being radially symmetrical, with a superior ovary. Flowers have the following components:

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s, four or five, which tend to persist;

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s four or five, usually yellow, sometimes dotted with black specks;

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s many, on long filaments; styles, three to five, often fused at the base. The fruit has a

dehiscent Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that op ...

capsule which splits open when ripe to release the fine black seed.

Taxonomy

At one time, this family was accepted as a subfamily of the family Clusiaceae. Now it has been elevated to full family status. In ''

Phytotaxa ''Phytotaxa'' is a peer-reviewed scientific journal for rapid publication on any aspect of systematic botany. It publishes on a wide range of subjects, but focuses on new species, monographs, floras, revisions, reviews, and typification issues. ...

'', six

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

and around 590

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

are listed, whereas ''

The Plant List The Plant List was a list of botanical names of species of plants created by the Royal Botanic Gardens, Kew and the Missouri Botanical Garden and launched in 2010. It was intended to be a comprehensive record of all known names of plant species ...

'' recognises nine genera and around 700 species. Members of the family are found worldwide except in excessively cold or dry areas. Most of the genera are mainly tropical, but ''

'' and ''

'' are found in temperate regions. Molecular data supports the

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of Hypericaceae. When accepted as a complete family, the cladogram of Hypericaceae would appear as such:

Pharmacology

Many members of this family contain the

naphthodianthrone ''For the parent molecule 9,10-anthraquinone, see anthraquinone'' Anthraquinones (also known as anthraquinonoids) are a class of naturally occurring phenolic compounds based on the 9,10-anthraquinone skeleton. They are widely used industrially and ...

derivatives hypericin and

pseudohypericin Pseudohypericin is an aromatic polycyclic dione that is very closely related to hypericin. It is found most commonly in the St. John's wort family of plants, namely in ''Hypericum perforatum''. In preliminary studies in animal models, pseudohyper ...

; these are contained in glandular tissues that appear as black, orange or translucent spots or lines on petals, leaves and other parts of the plant. These compounds are photosensitive and can cause reactions in grazing animals, such as blistering of the muzzle, as well as in people who come into contact with the plants over prolonged periods. The highest concentration of these substances occurs in common St. John's wort (''Hypericum perforatum''), which is used in

herbalism Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern reme ...

and as a folk remedy.

References

External links

Hypericaceae of Mongolia in FloraGREIF
{{Authority control

Hypericaceae 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. '' ...