Ovary (plants)


Ovary (plants)
Longitudinal section of female flower of squash showing pistil (=ovary+style+stigma), ovules, and petals

In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. Specifically, it is the part of the pistil which holds the ovule(s) and is located above or below or at the point of connection with the base of the petals and sepals. The pistil may be made up of one carpel or of several fused carpels, and therefore the ovary can contain part of one carpel or parts of several fused carpels. In this picture of a zucchini the petals and sepals are above the ovary and such a flower is said to have an inferior ovary; also referred to as epigynous. Above the ovary is the style and the stigma, which is where the pollen lands and germinates to grow down through the style to the ovary, and, for each individual pollen grain, to grow into one individual ovule. Some wind pollinated flowers have much reduced and modified ovaries.

Contents

Fruits

A fruit is the ripened ovary or ovaries—together with seeds—from one or more flowers. The fruits of a plant are responsible for dispersing the seeds that contain the embryo and protecting the seeds as well. In many species, the fruit incorporates some surrounding tissues, or is dispersed with some non-fruit tissues.

Parts of the ovary

  • Valves
  • Obturator

Classification based on position

Ovary insertion: I superior II half-inferior III inferior. a androecium g gynoecium p petals s sepals r receptacle. The insertion point is where a, p, and s converge.

The terminology of the positions of ovaries is determined by the insertion point, where the other floral parts (perianth and androecium) come together and attach to the surface of the ovary. [1] If the ovary is situated above the insertion point, it is superior; if below, inferior.

Superior ovary

A superior ovary is an ovary attached to the receptacle above the attachment of other floral parts. A superior ovary is found in types of fleshy fruits such as true berries, drupes, etc. A flower with this arrangement is described as hypogynous. An example is Hypericum calycinum.

An ovary becomes superior during anthesis (flower formation) when the upper portion of the ovary grows more than the lower part[citation needed].

Inferior ovary

An inferior ovary lies below the attachment of other floral parts. A pome is a type of fleshy fruit that is often cited as an example, but close inspection of some pomes (such as Pyracantha) will show that it is really a half-inferior ovary. Flowers with inferior ovaries are termed epigynous. Some examples of flowers with an inferior ovary are orchids (inferior capsule), Fuchsia (inferior berry), Asteraceae (inferior achene-like fruit, called a cypsela).

Half-inferior ovary

A half-inferior ovary (also known as “half-superior”, “subinferior,” or “partially inferior,”) is embedded or surrounded by the receptacle.[2] This occurs in flowers of the Lythraceae family, which includes the Crape Myrtles. Such flowers are termed perigynous or half-epigynous. In some classifications, half-inferior ovaries are not recognized and are instead grouped with either the superior or inferior ovaries.

More specifically, a half-inferior ovary has nearly equal portions of ovary above and below the insertion point. Other varying degrees of inferiority can be described by other fractions. For instance, a "one-fifth inferior ovary" has approximately one fifth of its length under the insertion point. Likewise, only one quarter portion of a "three-quarters inferior ovary" is above the insertion.

See also

References

  1. ^ Soltis et al.; Fishbein, Mark; Kuzoff, Robert K. (2003). "Evolution of Epigyny". International Journal of Plant Sciences 164 (S5): S251–S264. doi:10.1086/376876. 
  2. ^ Soltis & Hufford; Hufford, Larry (2002). "Ovary Position Diversity in Saxifragaceae". International Journal of Plant Sciences 163 (2): 277–293. doi:10.1086/324528. 

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Look at other dictionaries:

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  • Ovary — O va*ry ([=o] v[.a]*r[y^]), n.; pl. {Ovaries} ([=o] v[.a]*r[i^]z). [NL. ovarium, fr. L. ovum egg: cf. F. ovaire. See {Oval}.] 1. (Bot.) That part of the pistil which contains the seed, and in most flowering plants develops into the fruit. See… …   The Collaborative International Dictionary of English

  • ovary — /oh veuh ree/, n., pl. ovaries. 1. Anat., Zool. the female gonad or reproductive gland, in which the ova and the hormones that regulate female secondary sex characteristics develop. 2. Bot. the enlarged lower part of the pistil in angiospermous… …   Universalium

  • ovary — o•va•ry [[t]ˈoʊ və ri[/t]] n. pl. ries 1) anat. zool. the female gonad or reproductive gland, in which the ova and the female sex hormones develop 2) bot the enlarged lower part of the pistil in flowering plants enclosing the ovules or new seeds… …   From formal English to slang

  • Terminology for Asteraceae — NOTOC accrescent *Growing larger after flowering.1913] achene *achene *A small, dry, indehiscent fruit, containing a single seed, as in the buttercup; called a naked seed by the earlier botanists. *small dry indehiscent fruit with the seed… …   Wikipedia

  • Morphology of Pachypodium — Plants belonging to the genus Pachypodium vary widely from each other in some aspects, but also share a number of basic common traits. Each species is adapted to the specific environment which it inhabits, but all species of the genus share… …   Wikipedia

  • Ovaries — Ovary O va*ry ([=o] v[.a]*r[y^]), n.; pl. {Ovaries} ([=o] v[.a]*r[i^]z). [NL. ovarium, fr. L. ovum egg: cf. F. ovaire. See {Oval}.] 1. (Bot.) That part of the pistil which contains the seed, and in most flowering plants develops into the fruit.… …   The Collaborative International Dictionary of English

  • angiosperm — /an jee euh sperrm /, n. Bot. a plant having its seeds enclosed in an ovary; a flowering plant. Cf. gymnosperm. [ANGIO + SPERM] * * * ▪ plant Introduction       any member of the more than 300,000 species of flowering plants (division Anthophyta) …   Universalium

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  • Ericales — ▪ plant order Introduction   rhododendron order of flowering plants, containing 25 families, 346 genera, and more than 11,000 species.       The relationships of the order are unclear. It belongs to neither of the two major asterid groups… …   Universalium


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