T. This genus includes the mountain ashes (rowans) and white beams. They are mostly simple to grow in any reasonably fertile soil, with clusters of whitein May, followed by crimson berries. They are easily increased by sown in late summer in a cold frame. Sorbus aucuparia is the native mountain ash or rowan tree which eventually grows to about 50 ft. in good soil. The large red berries are nearly always taken by birds. S. a. moravica (edalis) has larger, edible berries and S. a. xanthocarpa is a yellow-fruited form. S. domestica is the service tree, about the same height, but the colour of the berries is less vivid. S. decora is slow-growing, making an erect, pyramidal tree. S. cashmeriana has fern-like foliage and extra large white berries. S. aria is the native white beam which does well in town gardens and in exposed positions generally. The foliage is bright green on the upper surface and white beneath. S. sargentiana has very large which assume reddish hues in autumn, and huge clusters of orange-red berries. The large, sticky buds resemble those of the horse chestnut.