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 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. Alternatively, the style can be closed (completely filled with cells). Most plants with syncarpous pistils ( monocotyledons 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 consists of several carpels, each of them may have a distinct ''stylodium'' (sometimes seen as a pseudo-style) or share a common style. In Iris and other species of the '' Iridaceae'' 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'', ''Pardanthopsis'', and in most species of the genus '' Moraea''. In '' Crocus'' species, the style is branched into three "branches," forming a tube. Plants of the genus '' Hesperantha'' have a spread-out branched style. The style can also be lobed rather than branched. Plants of the genus '' Gladiolus'' have a bilobed style. In the genera '' Freesia'', '' Lapeirousia'', '' Romulea'', '' Savannosiphon'', 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. 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''.

Pollination

Pollen tubes grow the length of the style to reach the ovules, and in some cases self-incompatibility reactions in the style prevent full growth of the pollen tubes. In some species, including '' Gasteria'' at least, the pollen tube is directed to the micropyle 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