Bat Pollination of the Passion Flower, Passiflora mucronata, in Southeastern Brazil

Abstract

The pollination by bats of the passion flower, Passiflora mucronata, has been studied in southeastern Brazil. Experiments indicate that the flowers are self-incompatible. They are typically chiropterophilous being white, long-stalked, and exserted from the foliage canopy, opening after dark, and producing nectar throughout the night. The flower opens in less than 15 seconds and shows subsequent movements of the anthers and stigmas which results in a zygomorphic flower, an uncommon condition in Passiflora. The grouping of anthers and stigmas increases the deposition of pollen on the head of the visiting bat and offers the greatest stigmatic surface to be brushed with pollen already deposited on the bat's head. Two species of phyllostomid bats, Glossophaga soticina (long-tongued) and Caorollia perspici iata (short-tongued), were observed pollinating the flowers. Other nocturnal visitors were sphingid and noctuid moths, and wasps, but all were ineffectual pollinators. The flowers of P. mucronata remain open until mid-morning and are visited by diurnal bees, wasps, butterflies, and hummingbirds, but it seems that only honeybees effect pollination, and their active foraging for pollen may prevent much of the potontial pollination by hummingbirds.