Stigma (botany)

Diagram of stigma

The stigma (plural: stigmata) is the receptive tip of a carpel, or of several fused carpels, in the gynoecium of a flower.

Description

Stigma of a Tulipa species, with pollen

The stigma, together with the style and ovary comprises the pistil, which in turn is part of the gynoecium or female reproductive organ of a plant. The stigma forms the distal portion of the style or stylodia. The stigma is composed of stigmatic papillae, the cells which are receptive to pollen. These may be restricted to the apex of the style or, especially in wind pollinated species, cover a wide surface. [1]

The stigma receives pollen and it is on the stigma that the pollen grain germinates. Often sticky, the stigma is adapted in various ways to catch and trap pollen with various hairs, flaps, or sculpturings. [2] The pollen may be captured from the air (wind-borne pollen, anemophily), from visiting insects or other animals ( biotic pollination), or in rare cases from surrounding water ( hydrophily). Stigma can vary from long and slender to globe shaped to feathery. [3]

Pollen is typically highly desiccated when it leaves an anther. Stigma have been shown to assist in the rehydration of pollen and in promoting germination of the pollen tube. [4] Stigma also ensure proper adhesion of the correct species of pollen. Stigma can play an active role in pollen discrimination and some self-incompatibility reactions, that reject pollen from the same or genetically similar plants, involve interaction between the stigma and the surface of the pollen grain.

Other Languages
Afrikaans: Stempel
العربية: ميسم
català: Estigma
čeština: Blizna
eesti: Emakasuue
فارسی: کلاله
Gaeilge: Stiogma
íslenska: Fræni
lumbaart: Stìgma
magyar: Bibe
македонски: Толчник (цвет)
Nederlands: Stempel (plant)
norsk nynorsk: Arr i botanikk
português: Estigma
Simple English: Stigma (botany)
Türkçe: Tepecik (bitki)
українська: Приймочка
中文: 柱頭 (花)