Samara

A samara is a type of fruit in which a flattened wing of fiberous, papery tissue develops from the ovary wall. A samara is a simple dry fruit and indehiscent (not opening along a seam). They are winged achenes. The shape of a samara enables the wind to carry the seed farther away from the parent tree. Examples include elms, maples and ash.

Definition from URL: http://en.wikipedia.org/wiki/Samara_(fruit)