There are two types of pollinations (chasmogamy) in chasmogamous flowers, i.e., self-pollination and cross-pollinations .
(a) Self-pollination(Autogamy) The transfer of pollen grains from anther to stigma of the same flower is called self-pollination. It is found in both cleistogamous and chasmogamous flowers.
(b) Cross-pollination (Allogamy) The transfer of pollen grains from anther to the stigma of another flower is called a cross-pollination . It is of two tpyes
(i) Geitonogamy it is the transfer of pollen from anther to the stigma of another flower of the same plant. It is functiconally a type of cross-pollination involving a pollinatins agent, genetically. It is similar to autogamy.
(ii) Xenogamy The transfer of pollen grains from the flower of one plant to the stigma of another plant. This is the only type of pollination, which brings genetically different types of pollen grains to the stigma.
