How flowers avoid self-pollination

Five adaptations by which flowers prevent their own pollen from reaching their own stigma.

Adaptation	What it is	Examples
Unisexual flowers	Flowers arise separately as pistillate and staminate flowers.	coconut, maize
Self-sterility	Fruit does not form when a flower's pollen is deposited on its own stigma.	passion fruit
Herkogamy	The stamens and the stigma of a flower are situated far apart from each other.	spider lily, orchid
Stamens bent outwards	When the stigma is straight the stamens are bent, or when the stamens are straight the stigma is bent.	pinna, jasmine
Dichogamy	The androecium matures before the gynoecium (protandry), or the gynoecium matures before the androecium (protogyny).	maize, Tridax

Figure to be added

Figure 14.9 — flowers with adaptations that prevent self-pollination: passion fruit, orchid and jasmine.

Separated in space, or separated in time

Five adaptations, but really only three tactics. Unisexual flowers and self-sterility rule the flower's own pollen out. Herkogamy and bent stamens separate the two parts in space. Dichogamy separates them in time — both parts are there, but never ripe at once.