XVI International Botanical Congess

Dichrostachys cinerea (Mimosoideae) a common shrub in peninsular India had inflorescence with pink neuter flowers at distal and functional yellow flowers at the apical end. These pink neuter flowers change colour to white on senescence. This study investigates the role of attractive pink neuter flowers on the male/female reproductive success of the species and its influence on pollinator behaviour. Dichrostachys cinerea was mainly pollinated by Xylocopa pubescens. The pollinators were exposed to plants with and without neuter flowers. Results showed that removal of the neuter had a strong effect on pollinator choice. The visitation rate was higher in controls compared to the experimental plants. Poor visitation did not depress the fecundity. The colour change in these flowers from pink to white on senescence also promotes male reproductive success by directing the pollinators to the right flowers. It is suggested that increasing male reproductive success could be the function of investment in such attractive neuter flowers.