BIOL 1902 Lecture Notes - Lecture 21: Pseudocopulation, Aposematism, Cornus Canadensis
17 Jun 2015
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Problem is an insect going around a flower will get the flowers pollen on its own stigmas. This is called self-pollination and means inbreeding which not a good thing even for flowers (better to outbreed to get a better genetic mixture for future survival of offspring). Thus flowers are geared for cross-pollination = outbreeding: solutions, has to be a chemical agreement between the pollen and the stigma for the tube to grow down. Sterility or self-incompatibility: another is spatial separation of the sexes. Male flowers on conifers are usually near the bottom of the tree and the females at the top. The females are on top so that the pollen from the male flowers cannot fall onto the female flowers. Each sex on a separate plant (dioecious: ex. White campions bear only male or female flowers on one plant: spatial placement in the same flower.
