(a) Dichogamy: The condition in which the maturation of stigma and anther takes place at different times so as to prevent self-fertilisation.
(b) Heterostyly: In this, anther and stigma are placed at different positions, so the pollens can not come in contact with stigma of the same flower.
(c) Herkogamy: It is the non-transferred of pollen from anther to stigma of the same flower due to a mechanical barrier between anther and stigma.
