How does protogyny promote cross-pollination in arum lilies and grasses?

Protogyny is a form of dichogamy that promotes cross-pollination by creating a temporal barrier to self-fertilization. In this process, the female reproductive organs (pistils) of a flower mature and become receptive to pollen before the male reproductive organs (stamens) on the same plant release their pollen.12

By ensuring that the stigmas are ready to receive pollen from a different source before the plant’s own pollen is available, the plant effectively inhibits self-pollination. This mechanism is found in arum lilies and many wind-pollinated grasses, forcing the plant to rely on external agents—such as insects or wind—to bring in pollen from other individuals. This outbreeding strategy is evolutionarily advantageous, as it increases genetic variability and helps ensure the survival of the species in changing environments.321