Cross-pollination is the transport of pollen from a single plant to a different plant by insects or the wind. It merges the hereditary characteristics of two plants and creates more varied species.
Cross-pollination works the opposite way of self-pollination, in which a plant transfers pollen grains to itself to produce fruits and seeds. Cross-pollinated species often generate stronger seeds than self-pollinated plants. The plants that result from cross-pollination adapt better to changes in the surroundings, compared to plants produced by self-pollination that sometimes fail to adjust. Species that use both self-pollination and cross-pollination typically produce a higher quality and number of seeds when they breed through cross-pollination. The most common pollinators are bees, which deliver pollen to other flowers as they collect nectar from flowers. Other pollinators include flies, moths and butterflies.
Dioecious plants, such as the willow, can produce seeds through cross-pollination only, because their male and female flowers are found on separate plants. In contrast, monoecious plants can use self-pollination, as they possess both male and female flowers on a single plant or sometimes in one flower. One of the artificial methods people use to prevent self-pollination in monoecious plants is by cutting or tying bags over the male flowers. Agriculturists apply cross-pollination in the creation of hybrid corn and numerous other kinds of hybrid flowers.