Pollination is the process by which pollen is transferred from the male anthers of a flower to the female stigma of a flower. This process is essential for the reproduction of plants and is typically carried out by insects, birds, small mammals or the wind.
Pollen comes in many sizes and forms, depending on the plant species; for example:
In wind-pollinated plants, the pollen produced by the anthers is released into the air and carried by the wind to other plants, where it may be caught by the stigma. In insect-pollinated plants, pollen is transferred from flower to flower by insects. They visit the flowers for nectar or to feed on pollen.
The table below compares the properties of insect-pollinated plants and wind-pollinated plants.
|Feature||Wind pollinated||Insect pollinated|
|Petals||Small dull petals, as there is no need to attract insects||Brightly coloured petals to help attract pollinating insects|
|Nectar||Do not produce nectar||They produce nectar, which is a sugary fluid to attract bees|
|Amount of Pollen grains||Produces large amounts of pollen – However, most pollen grains will not get to another flower||They produce smaller amounts of pollen, as insects are efficient at transferring pollen|
|Anthers||Hangs outside of the flower, attached to the long filaments, so the pollen can be taken away by the wind||Held firmly inside the flower, so any landing insects will brush against it|
|Stigma||Feathery or sticky and hanging outside of the petals to make it easier to trap pollen that is carried by the wind||Small and held inside the flower|
There are two main types of pollination: