Floral polymorphism and environmental heterogeneity
Polymorphism in flower colour may be maintained either by pollinator preferences or by environmental fluctuations. Tang and Huan examine gynoecium colour polymorphism in an emergent, aquatic monocot Butomus umbellatus and find that the major pollinator groups do not discriminate between the pink and white morphs. Instead, the plants differ in their tolerance to water level, thus demonstrating that flower colour polymorphism can be maintained by temporal or spatial heterogeneity of the environment
