The New Student's Reference Work/Dichogamy

Dichogamy (dī́-kŏg′ ȧ-my) (in plants).  The condition in flowers in which the stamens and pistils do not mature at the same time. For example, the stamens may be ready to shed pollen when the stigma is not yet ready to receive it, or the stigma maybe ready to receive pollen before the stamens are ready to shed it. There thus are two forms of dichogamy, one in which the stamens mature first (protandry), the other in which the stigma is ready first (protogyny).  See Pollination.