XVI International Botanical Congess

Dichrostachys cinerea (Mimosoideae) a common shrub produces pink neuter flowers at distal end and functional yellow flowers at the apical end. Pink neuter flowers change colour to white on senescence. This study investigates the role of attractive pink neuter flowers in the male/female reproductive success of the species and pollinator behaviour. Dichrostachys was visited by 3 species of carpenter bees and Xylocopa pubescens, accounted for 98% of the visits. Results show that removal of the neuter flower had a strong effect on pollinator choice at the plant and inflorescense levels. Plants without the neuter flowers were poorly visited but did not depress fecundity. It is suggested that increasing male reproductive success could be a reason for the attractive neuter flowers and color change could aid in directing pollinators to the right flowers.