All species have a characteristic of clones of each other fruits. They are very light, so that when the wind of fall it may spread over long distances. Placed in them the seeds with them may be moved away from home on the trees. This means, inter alia, that the spraying takes place in an easy manner. In some countries, the clones are the most common trees. This is true for example in Great Britain, where one of the species - sycamore maple najpospolitszy there. It is not a native species there, and owes its existence mainly to people who brought it from the other Channel. Probably happened when picked up trade between England and France.