Landscape Plants

Some 11 species of deciduous shrubs or small trees.  The number of species recognized by botanists has varied from as many as 60 (by "splitters") to as few as 3 (by "lumpers").  Leaves alternate or occasionally opposite, compound (trifoliate or 5-foliate).  Flowers in clusters, greenish-white, small, 4-5 each sepals and petals, both occasionally 6.  Fruit a samara, circular, winged. 
Ptelia: the Greek name of the elm tree, which has similar winged fruit.