Examine a few flowers of any cucurbit plant and try to identify the staminate and pistillate flowers. Do you know any other plant that bears unisexual flowers?
Let's take an example of a cucurbitaceae plants: Cucumber (Cucumis sativus) is an example of uni-sexual cucurbit which contain either male sex-organ (androecium) or the female sex-organ (gynoecium). On examining a cucumber (Cucumis sativus) plants, the staminate flower or male flower (containing male sex-organ i.e., androecium ). Whereas the pistillate flower grow on the different flower. It means that either their flower have male sex-organ or female sex-organ i.e., either androecium or gynoecium respectively, but never both. Hence, they require insects, like bees and flies for pollination as their pollen grains are sticky & cannot be wind-blown.
