Rowan Several of the Asian species are widely cultivated as ornamental trees. North American native species in the subgenus "Sorbus (Sorbus)" include the American mountain-ash "Sorbus americana" and Showy mountain-ash "Sorbus decora" in the east and Sitka mountain-ash "Sorbus sitchensis" in the west. Numerous hybrids, mostly behaving as true species reproducing by apomixis, occur between rowans and whitebeams; these are variably intermediate between their parents but generally more resemble whitebeams and are usually grouped with them (q.v.). Rowans are excellent small ornamental trees for parks, gardens and wildlife areas. Several of the Chinese species, such as White-fruited rowan ("Sorbus glabrescens") are
Sorbus aucuparia a light brown to reddish brown heartwood. It is diffuse-porous, flexible, elastic, and tough, but not durable, with a density of 600 to in a dried state. The roots of "S. aucuparia" grow wide and deep, and the plant is capable of root sprouting and can regenerate after coppicing. The compound leaves are pinnate with 4 to 9 pairs of leaflets on either side of a terete central vein and with a terminal leaflet. There are paired leaf-like stipules at the base of the petiole. The leaves are up to 20 cm long, 8 to 12 cm wide, and arranged