Pollination

Vismaya c p

Updated on August 25, 2022

Pollination is the process of transfer of pollen grains from the anther to the stigma of a flower. Flowering plants have different adaptations and mechanisms to achieve pollination.

Table of Contents

Types of pollination

Pollination can be divided into 3 types based on the source of pollen. They are

Autogamy
Geitonogamy
Xenogamy

Autogamy is also known as self-pollination. it is the transfer of pollen grains from anther to stigma of the same flower.

Geitanogamy is the transfer of pollen from anther to the stigma of another flower of the same plant. Genetically geitonogamy is similar to autogamy because pollen grains come from same plant but functionally geitonogamy is cross-pollination because it involves a pollinating agent.

Xenogamy is the transfer of pollen grains from the anther to the stigma of a flower of different plant.

Agents of pollination

In plants, pollen grains cannot move on their own so they need some external agents to get transferred to the stigma. plants use both biotic and abiotic agents for pollination. a majority of plants use biotic agents for pollination. plants produce large number of pollen grains for increasing the probability of pollination. Every flower is modified according to their pollinating agents.

Biotic agents include animals, insects, birds, bats etc wind and water are the abiotic agents.

Based on the agents of pollination, pollination can be again divided into many types. they are

Pollination by biotic agents

Entamophily
Ornithophily
Chiropterophily
Malacophily
Myrmecophilly

Pollination by Abiotic agents

Anemophily
Hydrophily

Entamophily-(Pollination by insects)

Pollination by insects is termed as entamophily. insect-pollinated flowers are usually brightly coloured, scented and rich in nectar. this adaptation is mainly for attracting insects for pollination.nectar and pollen grains are the rewards given to the insects.

Ornithophily-( Pollination by birds)

Pollination by birds is known as ornithophily. Ornithophillous flowers are also brightly coloured(usually red coloured), less fragrant and rich in nectar. flowers will be tubular or bell-shaped to ease the entry of beak of birds.These flowers have bright colors of larger wavelength which are visible to the birds from long distance and flowers are usually less fragrant.

Chiropterophily- (Pollination by bats)

Around 530 species of flowering plants depends on bats for pollination either as exclusively or as major pollinator. Most tropical plants are pollinated by fruit-eating or nectar-eating birds. Flowers pollinated by bats usually bloom at night and are white or dull in colour and have a rotten smell. flowers will be large in size and rich nectaries are present.

Malacophily (Pollination by snails)

Malacophily is the pollination by snails. plants belongs to the arum family are mainly pollinated by snails. Flowers will be large and with a dull smell.

Myrmecophilly (pollination by Ants)

Pollination by ants is termed as Myrmecophily. Ants can also pollinate flowers but they cannot be considered as major pollinators. Ant secretes antibiotics which hinder the pollination.

Pollination by abiotic agents

Water and wind are the abiotic agents of pollination

Anemophily ( Pollination by wind)

Pollination by wind is known as anemophily. the wind is an abiotic agent of pollination. there are certain features for wind pollinating flowers. Anemophilous flowers will be small which is usually seen as inflorescence. Flowers will not be brightly coloured or scented. Feather stigma and versatile anthers are present in anemophilous flowers. The plant produces a large amount of non-sticky, weightless and dry pollens so it can easily carried by the wind. Large amounts of pollen are wasted here. Anther and stigma will be well exposed .wind pollinated flowers will not have bright colours, fragrances or nectar.

Hydrophily (Pollination by water)

Pollination by water is called hydrophily. they are of two types Epihydrophily and hypohydrophily

Epihydrophily takes place on the surface of water and hypohydrophily takes place inside the water. The hydrophilous flower will be small, colourless, odourless, and nectarless and the stigma will be long. pollen grains are protected by mucilaginous covering.

Pollination

Vismaya c p

Types of pollination