Those that cannot self pollinate rely on a variety of pollinators. The secret of success is to attract the pollinators to flowers of your species rather than those of others, using a combination of time of opening, number of flowers, smell, movement, size, shape & colour. Each species is in competition with not just other Passiflora but every flower in the rain forest. At the same time it is a delicate balance as its generally accepted to be a fatal error for both plant & pollinator to become exclusively dependent on each other. Passiflora parritae is thought to have this problem.
Most Passiflora have flowers that are attractive to one type of pollinator e.g. bats, bees, butterflies, flies, hummingbirds, moths or wasps. A few depending on the time of day and their changing shape attract multiple pollinator types. Others attract the attentions of butterflies such as Agraulis vanillae, the Gulf Fritillary, which as well as possibly pollinating the plants wqhen drinking nectar lay eggs on them & use them as caterpillar food. See Androgynophore movement for a Passiflora Section Xerogona flower that can bend towards its hummingbird pollinator.
Some Passiflora can self pollinate without needing visitors to the flowers. One that selfs naturally in the wild (& in my kitchen over winter) with perhaps the slightest wind is the very invasive P. suberosa. The downside of this ability however, is that if it selfs too easily it is more likely to be stuck with its existing genetic material, so if conditions change it may not be able to adapt. I have discussed elsewhere, in Pollen, the range of options between self fertile & self sterile which Passiflora employ. In some the stigma will even curve down as the day progresses which increases the chances of selfing if no pollen from elsewhere has been deposited.
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