Elm samara, sámara de olmo

A samara is a type of fruit in which a flattened wing of fibrous, papery tissue develops from the ovary wall. It is a simple dry fruit and indehiscent (not opening along a seam). It is a winged achene. The shape of a samara enables the wind to carry the seed farther away than regular seeds from the parent tree.
The Field Elm tree typically grows to < 30 m and bears a rounded crown. The bark of the trunk is rough, furrowed lightly in older trees to form a block pattern. Young branchlets occasionally have corky wings. The leaves are smaller than those of the other European species, hence the specific epithet minor, however they can vary greatly according to the maturity of the tree. Leaves on juvenile growth (suckers, seedlings etc.) are coarse and pubescent, whereas those on mature growth are generally smooth, though remaining highly variable in form; there are generally fewer than 12 pairs of side veins. A common characteristic is the presence of minute black glands along the leaf veins, detectable with the aid of a magnifying glass. The samarae are typically ovate and notched, the notch extending to the central seed.