pistil
pistil
pis·til
P0331400 (pĭs′təl)pistil
(ˈpɪstɪl)pis•til
(ˈpɪs tl)n.
pis·til
(pĭs′təl)| Noun | 1. |  pistil - the female ovule-bearing part of a flower composed of ovary and style and stigma |
| 单词 | pistil | |||
| 释义 | pistilpistilpis·tilP0331400 (pĭs′təl)pistil(ˈpɪstɪl)pis•til(ˈpɪs tl)n. pis·til(pĭs′təl)
pistilpistil(pĭs`tĭl), one of the four basic parts of a flowerflower,name for the specialized part of a plant containing the reproductive organs, applied to angiosperms only. A flower may be thought of as a modified, short, compact branch bearing lateral appendages. ..... Click the link for more information. , the central structure around which are arranged the stamens, the petals, and the sepals. The pistil is usually called the female reproductive organ of a flowering plant, although the actual reproductive structures are microscopic. The pistil has a bulbous base (the ovary) containing the ovules, which develop into seeds after fertilization of egg cell(s) in the ovule. A pistil is composed of one or more highly modified leaves (carpels), each containing one or more ovules. A flower may have one or more simple pistils, each a separate organ, or, in higher orders, a compound pistil, formed of several fused carpels. Usually, there is above the ovary a stalk (the style) bearing on its tip the stigma, where the pollen grains land and germinate (see pollinationpollination, transfer of pollen from the male reproductive organ (stamen or staminate cone) to the female reproductive organ (pistil or pistillate cone) of the same or of another flower or cone. ..... Click the link for more information. ). The stigma is often sticky or hairy, to retain the pollen. Evolutionary relationships can often be inferred from the location of the ovary in relation to the other parts of the flower. If the stamens, petals, and sepals are attached beneath the ovary, the flower is hypogynous and the ovary is superior; if they are attached above, the ovary is inferior and the flower epigynous; if the ovary is located in a receptacle at the outer edges of which are attached the other flower parts, it is called superior or half-inferior and the flower perigynous. A flower that has one or more pistils but no stamens (or nonfunctional ones) is called pistillate, or female, as distinguished from a staminate, or male, flower, in which the pistil is nonfunctional or absent. Pistilthe reproductive organ of a flower. The pistil, which is located in the center of the flower, typically consists of a hollow and enlarged inferior part—the ovary, a slender and usually cylindrical style or a stylodium, and a stigma. The stigma usually crowns the style or stylodia. If the stylodia are reduced, the stigma sits directly on the ovary. The ovary contains ovules, from which seeds develop after fertilization. The pericarp develops from the walls of the ovary. Thus, the pistil as a whole participates in formation of the fruit. Many botanists consider the term “pistil” to be superfluous because it is synonymous with the apocarpous gynoecium (a simple pistil formed from a single carpel or several free carpels) or with the cenocarpous gynoecium (a compound pistil formed from two or more united carpels). pistil[′pist·əl]pistilpistil
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