Pollination is the process that enables the male and female parts of a flower to combine and reproduce. Essentially, pollen is transferred to the stigma of another. This fertilises an egg which then grows. A plant can pollinate itself, but more commonly, water, wind or insects facilitate the process. Wind and insect pollination is different in several ways.
Pollen Transfer with Insects
Insects pollinate flowers by picking up pollen on their legs. The pollen is then carried by the animal directly from one plant to another. The insect does not do this intentionally. While it is eating, its legs brush against the pollen accidentally. The pollen is then rubbed off onto the stigma of the next flower it visits.
Pollen Transfer with Wind
Unlike insects, which carry the pollen between flowers, the wind blows pollen between plants to aid sexual reproduction. The pollen is carried in the air. Hay fever is an allergy to pollen in the air. More pollen is carried by wind than insects; it is a more random pollination process. Insects are able to move pollen directly between plants, whereas the wind changes and cannot direct pollen to exactly where it needs to land.
Flowers Pollinated by Insects
The types of plants fertilised by insects and winds are different. Insects fertilise flowers that have a scent, are brightly coloured and supply nectar. Flowers have these characteristics to attract the insect to them, so they can reproduce. Bees pollinate snapdragons, while butterflies tend to pollinate pink or lavender coloured flowers with large petals, for example.
Plants Pollinated by Wind
Plants pollinated by the wind have both the male and female reproductive organs, unlike those pollinated by insects. These include cereals, wheat, grasses and some trees. They are not as attractive or bright as those pollinated by insects, because they do not need to lure the insects to their pollen. Cattails, pussy willows and catkins are pollinated by the wind. Flowers pollinated by the wind tend to be small, green and lack petals, such as the black walnut.