Rowan Rowan The rowans or mountain-ashes are shrubs or trees in the genus "Sorbus" of the rose family, Rosaceae. They are native throughout the cool temperate regions of the Northern Hemisphere, with the highest species diversity in the mountains of western China and the Himalaya, where numerous apomictic microspecies occur. The name "rowan" was originally applied to the species "Sorbus aucuparia" and is also used for other species in "Sorbus" subgenus "Sorbus". Formerly, when a wider variety of fruits were commonly eaten in Europe and North America, "Sorbus" was a domestically used fruit throughout these regions. It is still used in
Sorbus aucuparia larger forest trees. In Central Europe it often grows in association with red elderberry, goat willow, Eurasian aspen, and silver birch. The plant is highly flammable and tends not to accumulate plant litter. Other species of the genus "Sorbus" easily hybridize with "S. aucuparia" and hybrid speciation can result; hybrids include "Sorbus × hybrida", a small tree with oval serrated leaves and 2 to 3 pairs of leaflets, which is a hybrid with "Sorbus × intermedia", and "Sorbus thuringiaca", a medium-size tree with elongated leaves and 1 to 3 pairs of leaflets that are sometimes fused at the central vein,