A samara is a type of dry fruit where one seed is surrounded by papery tissue that helps carry the seed away from the tree as the wind blows. The fruit does not split open, which means that it is indehiscent. They are often found in large groups on the tree.
Not all samaras look alike. One familiar type of samara is the double-winged one found on maple trees (Acer spp.). Ash trees (Fraxinus spp.) produce a samara that features a single elongated wing. Elm trees (Ulmus spp.) produce samaras where the seed is located in the middle of a papery circle.
Examples of other trees and shrubs that produce samaras: