Many tall trees have winged seeds that travel some distance before falling on the ground to germinate. This prevents new plants from growing too close to the parent plants.
The Anisoptera, one of the tallest trees in Asia, has seeds that have two wings. The seeds are shaped like spears and they curve upwards and outwards. The wings are unequal in length and spin like propellers of a helicopter when released.
The Alsomitra is another tall tree with winged seeds. Its seeds are fitted with paper-thin, almost transparent wings. When released, they descend very slowly and travel for a distance of over a hundred yards before falling to the ground.