General - a smooth-barked deciduous shrub or small tree up to 10 m high with a short trunk, slender, spreading branches, and a narrow, open round-topped crown; similar to American Mountain Ash but winter buds are sticky. alternate; compound with 13-17, similar to American Mountain Ash but shorter and more rounded at the base, serrate or doubly serrate leaflets. numerous in showy round or flat-topped clusters 5-15 cm diameter; individual, 5-petaled flowers, small, 6-8 mm wide; appearing June and July.