Gynoecium

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Amaryllis style and stigmas
Flowers and fruit of the ground orchid, Spathoglottis plicata: its 'inferior' ovary lies below the attachment of other floral parts
Parts of a Ranunculus (buttercup) flower
A large stigma with anthers in the background
The gynoecium of an apple has five carpels

A gynoecium (from Ancient Greek gyne, "woman") is the female reproductive parts of a flower. The male parts are called the androecium. Some flowers have both female and male parts, and some do not.

Another key term is carpel. Carpels are the building blocks of a pistil. The gynoecium may have one pistil or more. A pistil may have one carpel or more than one stuck together ("fused"). Carpels and pistils have three parts: a stigma at the top where the pollen lands; a style and an ovary. In the case of a pistil, the stigma, style, and ovary may be made up of those parts of more than one carpel, fused.

Plant ovaries are the parts of the gynoecium which (much like animal ovaries) contain ovules. The style is generally stalklike. It is between the ovary at the bottom and the stigma at the top. In some plants, there are no styles in the pistils. The stigma is the pollen receptor at the top of the carpel. Stigmas may be separate or they may be in a region called the "stigmatic region".[1]

Carpel anatomy[change | change source]

A carpel is the basic unit of the female reproductive organ of a flower (the gynoecium). The parts of the carpel are:

  • the stigma: the end portion which receives the pollen. It is usually sticky;
  • the style, a stalk connecting the stigma with the ovary. It has a tract, which helps the growth of the pollen tube so the male gamete gets to the ovule; and
  • the ovary has the female reproductive cell or ovule.

The ovule[change | change source]

The ovule, when mature, has one or two coats round the central nucellus, except at the top where an opening, the micropyle, is left. The nucellus is a tissue round one large cell, the embryo-sac or megaspore. The one large cell divides, giving the egg and some other material.

An example of a simple carpel is that of a pea, bean or Arabidopsis: the fruit develops from the single carpel consisting of two rows of ovules aligned beside one another along the placental margin.

Pistil[change | change source]

An alternative term for the female parts. This table shows how it is used:

Comparison of gynoecium terminology using carpel and pistil
Gynoecium composition Carpel
terminology
Pistil terminology Examples
Single carpel Monocarpous (unicarpellate) gynoecium A pistil (simple) Avocado (Persea sp.), most legumes (Fabaceae)
Multiple distinct (unfused) carpels Apocarpous (choricarpous) gynoecium Pistils (simple) Strawberry (Fragaria sp.), Buttercup (Ranunculus sp.)
Multiple connate

("fused") carpels

Syncarpous gynoecium A pistil (compound) Tulip (Tulipa sp.), most flowers

Further reading[change | change source]

  • Esau K. 1965. Plant anatomy. 2nd ed,. John Wiley.
    • Simpson M.G. 2006. Plant systematics. Elsevier Academic Press, 374-375.