Try this investigation During Winter and Spring, look for a population of Sorrel plants in flower. Collect flowers from a number of different clumps. Open up the flowers and look at the arrangement of male and female parts inside. You should find similar numbers of three different arrangements of stamens and pistils (see diagram). When a bee visits a flower with a short style, it will collect pollen from medium and long stamens. If it visits another flower of the same clone, the pollen will not reach the stigma and self-pollination will be avoided. Look at the other flowers and see how this mechanism works in the other cases.