What's the "een" in Halloween?
The transfer of pollen from a male reproductive structure (an anther or male cone) to a female reproductive structure (a stigma or female cone) of the same plant or of the same flower. Self-pollination tends to decrease the genetic diversity (increase the number of homozygous individuals) in a population, and is much less common than cross-fertilization. Many species of plants have evolved mechanisms to promote cross-pollination and avoid self-pollination, though certain plants, such as the pea, regularly self-pollinate. Compare cross-pollination.