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".
Carpel anatomy[change | change source]
- 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.
Pistil[change | change source]
An alternative term for the female parts. This table shows how it is used:
|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.)|
|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.