Maple seeds - the samara
samara is a dry fruit and is indehiscent. Dehiscent means that a fruit naturally opens along a seam. Think about a milkweed pod. When it is young, it is light green, soft and tightly closed. As it matures in the fall, the outer covering turns a light gray, hardens and, finally, splits along a seam from the tip to the base of the pod. The halves of the pod peel back, and the silky tufts of fine hairs, with a seed attached at the bottom, float away in the wind.
Maple seeds, being indehiscent, don't split along a seam. That was something we had to do for ourselves to be able to stick the halves on our noses.
Sugar maples aren't the only trees that have samara. It's a characteristic of all maples. Silver, red, mountain, stripped, black and Norway maples in this region all produce seeds with wings. Maples, the genus Acer, around the planet have winged seeds making it easy to recognize maple trees. Ash trees also have seeds with wings, as do elms, hoptrees and pines.