botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

, the style of an angiosperm flower is an organ of variable length that connects the

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

to the stigma. The style does not contain ovules; these are limited to the region of the

gynoecium Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

(female organs of the flower) called the "ovary".

Structure

The style is a narrow extension of the ovary, usually pointing upwards, connecting the ovary to the stigmatic papillae. It may be absent in some plants; in this case, it is referred to as a

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

stigma. Styles generally resemble more or less long tubes. The style can be open (with few cells occupying the central part, or even none), featuring a central canal that may be filled with

mucilage Mucilage is a thick gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion, with the direction of their movement always opposite to that of the secretion of ...

. Alternatively, the style can be closed (completely filled with cells). Most plants with syncarpous pistils (

monocotyledons Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks and ...

and some eudicotys) have open styles, whereas many eudicots and grasses have closed (solid) styles containing specialized secretory tissues, which connect the stigma to the center of the ovary. These tissues form a nutrient-rich cord for the growth of the pollen tube. When the

pistil Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

consists of several

carpels Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ...

, each of them may have a distinct ''stylodium'' (sometimes seen as a pseudo-style) or share a common style. In

Iris Iris most often refers to: *Iris (anatomy), part of the eye * Iris (color), an ambiguous color term *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (given name), a feminine given name, and a list of peopl ...

and other species of the ''

Iridaceae Iridaceae () is a family of plants in order Asparagales, taking its name from the Iris (plant), irises. It has a nearly global distribution, with 69 accepted genera with a total of about 2500 species. It includes a number of economically importan ...

'' family, the style divides into three "petaloid branches" (resembling petals), sometimes also called stylodiums, almost at the origin of the style and is called "tribrachiate". These are strips of tissue emerging from the perianth tube above the sepal. The stigma is a ridge or edge on the lower surface of the branch, near the tip of the lobes. Branched styles also appear in the genera ''

Dietes ''Dietes'' is a genus of six rhizomatous plant species of the iris family Iridaceae, first described collectively in 1866. Common names for the different species include wood iris, fortnight lily, African iris, Japanese iris and butterfly iris. ...

'', ''Pardanthopsis'', and in most species of the genus ''

Moraea ''Moraea'', the Cape tulips, is a genus of plants in the family Iridaceae, first described as a genus in 1758. The group is widespread across Africa, the Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, ...

''. In ''

Crocus ''Crocus'' (; plural: crocuses or croci) is a genus of seasonal flowering plants in the family Iridaceae (iris family) comprising about 100 species of perennial plant, perennials growing from corms. They are low growing plants, whose flower stem ...

'' species, the style is branched into three "branches," forming a tube. Plants of the genus ''

Hesperantha ''Hesperantha'' is a genus of cormous flowering plants in the family Iridaceae. The genus name is derived from the Greek words ''hesperos'', meaning "evening", and ''anthos'', meaning "flower". There are approximately 79 species, mostly native t ...

'' have a spread-out branched style. The style can also be lobed rather than branched. Plants of the genus ''

Gladiolus ''Gladiolus'' (from Latin, the diminutive of ''gladius'', a sword) is a genus of perennial cormous flowering plants in the iris family (Iridaceae). It is sometimes called the 'sword lily', but is usually called by its generic name (plural ''g ...

'' have a bilobed style. In the genera ''

Freesia ''Freesia'' is a genus of herbaceous perennial flowering plants in the family Iridaceae, first described as a genus in 1866 by Christian Friedrich Ecklon (1886) and named after the German botanist and medical practitioner, Friedrich Freese (179 ...

'', ''

Lapeirousia ''Lapeirousia'' is a genus in the plant family Iridaceae. It is endemic to sub-Saharan Africa, about a third of the species occurring in fynbos. Origin of genus name The genus ''Lapeirousia'' was described by Pierre André Pourret in Mém. Aca ...

'', ''

Romulea ''Romulea'' is a genus of flowering plants in the family Iridaceae, first described as a genus in 1772. It is found in Europe, the Mediterranean, the Arabian Peninsula, and Africa.Savannosiphon ''Savannosiphon'' is a flowering plant genus in the family Iridaceae, circumscribed in 1980. It contains a single species, ''Savannosiphon euryphylla'', native to tropical Africa (Zaire, Tanzania, Malawi, Mozambique, and Zimbabwe).Geerinck, D (2 ...

'', and '' Watsonia'', the style has bifurcated and curved branches.

Attachment to the ovary

May be terminal (apical), subapical, lateral, gynobasic, or . Terminal (apical) style position refers to attachment at the apex of the ovary and is the most common pattern. In the subapical pattern, the style arises to the side slightly below the apex. A lateral style arises from the side of the ovary and is found in

Rosaceae Rosaceae (), the rose family, is a family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus '' Rosa''. The family includes herbs, shrubs, and trees. Most species are deciduous, but som ...

. The gynobasic style arises from the base of the ovary, or between the ovary lobes and is characteristic of

Boraginaceae Boraginaceae, the Borago, borage or forget-me-not family, includes about 2,000 species of shrubs, trees, and herbs in 146 to 154 genus, genera with a worldwide distribution. The APG IV system from 2016 classifies the Boraginaceae as single famil ...

. styles characterise ''

Allium ''Allium'' is a large genus of monocotyledonous flowering plants with around 1000 accepted species, making ''Allium'' the largest genus in the family Amaryllidaceae and among the largest plant genera in the world. Many of the species are edible, ...

''.

Pollination

Pollen tubes grow the length of the style to reach the

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the sporangium, megasporangium), ...

s, and in some cases self-incompatibility reactions in the style prevent full growth of the pollen tubes. In some species, including ''

Gasteria ''Gasteria'' is a genus of succulent plants, native to South Africa and the far south-west corner of Namibia. Naming The genus is named for its stomach-shaped flowers (''"gaster"'' is Greek for "stomach") that result from the swollen base on the ...

'' at least, the pollen tube is directed to the

micropyle Micropyle may refer to: * Micropyle (botany) a minute opening in the integument of an ovule of a seed plant. * Micropyle (zoology) A micropyle is a pore in the membrane covering the ovum, through which a sperm enters. Micropyles are also found in s ...

of the ovule by the style.Christophe Clement, Ettore Pacini, Jean-Claude Audran (Editors)

References

Sources

* * {{cite book , last=Simpson, first=Michael G., title=Plant Systematics, year=2011, publisher=Academic Press, isbn=978-0-08-051404-8, url=https://books.google.com/books?id=Ia2eIPVksMMC Plant reproduction Plant morphology