Pollination: It is defined as the transfer of pollen grain from the anther to the stigma of the same or another flower belonging to the same species.
Types of pollination
1) Self pollination(autogamy)
It is defined as the transfer of pollen grain from anther to the stigma of the same flower. It takes place in bisexual flower.
i) Homogamy: When the anther and the stigma of a bisexual flower mature at the same time, self pollination is very easily achieved.
ii) Cleistogamy: In few flowering plants, within the closed petals, stamens come in contact with the pistil and self pollination is brought about.
2) Cross pollination(allogamy)
It is defined as the transfer of pollen grains from anther of a flower to the stigma of of another flower of same plant or different plant of same species.
i) Geitonogamy: The transfer of pollen grains from anthers to the stigma of another flower borne on the same plant is called geitonogamy.
ii) Xenogamy: The pollination between two flowers of different plant of same species is called xenogamy.
Depending upon the agents of pollination it is classified into fallowing
a) Hydrophily: Pollination by water e.g. Hydrilla, Seneria
b) Anemophily: Pollination by wind. e.g. Maize.
c) Zoophily: Pollination by animals. Salvia
i) Entomophily: Pollination by insects e.g. Bougainvillea
ii) Ornithophily: Pollination by birds. e.g. silk cotton
iii) Chiropterophily: Pollination by bats e.g. Kadamba tree