These small, deciduous trees have rather large, scaly buds. Pinnately compound leaves are borne alternately along the stems. Flowers are showy, perfect, and borne in flat-topped corymbs.
Fruit is a red pome and borne in showy clusters.
Winter bud scales are white, woolly, and not sticky. Young branches are pubescent. Stipules are broad and coarsely toothed. May. Fruit is orange-red and matures in August or September. Mountain-Ash Winter bud scales are glabrous, or ciliate at the most, and sticky.