Behavioural responses of pollinators to variation in floral display size and their influences on the evolution of floral traits

The number of flowers open at any one time on a plant, i.e., floral display size, varies greatly among plant species. For example, some species flower during a brief period and have many open flowers, while others have extended flowering with only a few open flowers at one time (Gentry 1974; Bawa 1983). Also, floral display size often varies among individuals of the same plant species (e.g., Willson & Price 1977; Pleasants & Zimmerman 1990). The causes of such variations in floral display size are enduring interest to plant ecologists (reviewed by de Jong et al. 1992).