samara

noun

(L. samara: elm seed) A dry single-seeded indehiscent fruit in which the fruit wall hardens and extends to form a long membranous wing-like structure that aids dispersal. Examples are ash, maple and elm fruits. (The wing may be limb-like or envelop the seed and be wafer-like). The sycamore fruit is a double samara and technically a schizocarp. See also achene.