XVI International Botanical Congess

The literature on dioecious plants was surveyed to determine whether sexual dimorphism in vegetative and reproductive characters results in consistent sexual differences in competitive ability, or in damage from herbivores and parasites. Herbivores have been found to feed preferentially on male plants in a large number of dioecious species. However, there are few experimental data supporting the hypothesis that male and female plants differ in competitive ability, and the documented sexual differences in parasitism are not consistent in direction. Many sexual differences in characters affecting the outcome of biotic interactions can be attributed to the fundamental difference between male and female plants in the timing and magnitude of reproductive allocation.