Wind

Wind is one of the main agencies of seed dispersal. The way it transports them depends on the type of seed and where it grows.

Some tall trees produce seeds with stiff wings covering the seed that enable them to fly long distances. The wings are twisted and balanced so that the seed spins around as it is carried along by the wind. These natural adaptations for using the wind to transport the weight of the seed must be technically accurate, as the wings of modern planes and helicopters are designed in the same way.

These wings usually support one seed each, but may start off as a two-winged pod that later splits in two to release the seeds. Some seeds have only one wing (e.g. Lime or Ash). This type of attachment is quite heavy, and this system only works well in a good wind, and from a tall tree.

Sometimes seeds have thin wings as an extension of the seed that enable them to glide in the wind. They don't need so much wind as the seeds that fly, but they are not so heavy. The largest of this type of seed is 6" across, from a climber called Alsomitra growing in the tropical forests of Asia.

Some seeds have long, feathery tails which help them to fly, like the tail of a kite.