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.
Characteristics
Members of this family are
annual or
perennial 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 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
Etymology
The term ''sepalum'' ...
s, four or five, which tend to persist;
petals four or five, usually yellow, sometimes dotted with black specks;
stamens many, on long filaments;
styles, three to five, often fused at the base. The fruit has a
dehiscent 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'', six
genera and around 590
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
are listed,
whereas ''
The Plant List'' 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 ''
Hypericum'' and ''
Triadenum'' are found in temperate regions.
Molecular data supports the
monophyly 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 derivatives
hypericin and
pseudohypericin; 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 and as a
folk remedy.
References
External links
Hypericaceae of Mongolia in FloraGREIF
{{Authority control
Hypericaceae