Sorbus minima Sorbus minima Sorbus minima, commonly known as the lesser whitebeam or least whitebeam, is a shrub belonging to the subgenus "Aria" (whitebeams) in the genus "Sorbus". It is endemic to Wales where it grows at a few sites in Breconshire. It is an apomictic microspecies which reproduces asexually and so is reproductively isolated from its close relatives such as the Swedish whitebeam, "S. intermedia". It probably originated as a hybrid between the rock whitebeam ("S. rupicola") and the rowan ("S. aucuparia"). It was first discovered in 1893 by Augustin Ley, the vicar of Sellack in Herefordshire who travelled widely in
Fraxinus excelsior narrow crown. The bark is smooth and pale grey on young trees, becoming thick and vertically fissured on old trees. The shoots are stout, greenish-grey, with jet black buds (which distinguish it from most other ash species, which have grey or brown buds). The leaves are opposite, long, pinnately compound, with 7–13 leaflets with coarsely serrated margins, elliptic to narrowly elliptic, long and broad and sessile on the leaf rachis. There are no stipules. These features distinguish ash from mountain ash ("Sorbus aucuparia") in which the leaves are alternate with paired stipules. The leaves are often among the last to