I am not talking about any aphrodisiac fruit but only about fruit trees that exhibit varieties of sexual behavior.
Gender galore: While many wild fruit trees (also some cultivated) have male and female flowers in separate trees, some like Papaya are really sexy! Some varieties of Papaya bear male, female, male-female, neither completely male nor completely female flowers either on the same tree or on different trees.
Occasional sex changers: Some papaya trees even change sex depending on weather conditions. A male tree becomes female and vice versa depending on weather! What is more – if you behead a male papaya tree (males don’t produce useful fruits), chances are that it would become female when new shoots grow from the stump! They say that if there is a lone male papaya tree with no female tree in the vicinity, it automatically becomes female! – But I am not sure about this last one.
Habitual sex changers: There are fruit trees such as Sugar apple (and others in the family) and Avocado, that have the habit of changing sex every now and then! A sugar apple flower which is otherwise bisexual acts like female for few hours and changes into a male the next day! Similar thing happens in Avocado. So if all flowers decide to change to same sex same time, there is no way you can expect any fruits from that tree!
Some need help: Some fruits such as Cherimoya cannot pollinate on their own. They need human intervention – manual pollination.
No to consanguineous unions: It is not just humans; even fruit trees such as some varieties of Apples, Avocado, and so on shun consanguineous unions. To bear fruit, you need at least two different varieties in the same garden, even if trees bear bisexual flowers. Some are even choosier. They need a specific variety for cross pollination!
If you ponder over why all these gimmicks, you probably understand the complete philosophy behind union and procreation.