Anbe/biol 356/656

Floral-color Changes Floral-color changes are common among the angiosperms. At least three non-exclusive hypotheses have been proposed to explain these changes: 1. Once flowers are adequately pollinated, further pollinator visits impair reproduction by deposition of self-pollen, dislodging of pollen, or damage to floral parts. 2. Color changes mark flowers that have been depleted of their rewards (nectar or pollen). This could be advantageous to the plant in that it would make the plant more rewarding to pollinators and hence more likely to be visited. 3. Color changes mark sexually non-functional flowers, minimizing pollinator removal of inviable pollen or deposition of pollen on non-receptive stigmas.