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
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,