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
Burrington Combe as a Site of Special Scientific Interest in 1952. The calcareous grasslands support a diverse flora which includes Salad burnet ("Sanguisorba minor"), Knapweed ("Centaurea scabiosa" and "Centaurea nigra"), Rock-rose ("Helianthemum nummularium") and Wild thyme ("Thymus praecox"). On the higher, more acidic, slopes Goldenrod ("Solidago virgaurea"), Wood sage ("Teucrium scorodonia") and Common Bent ("Agrostis capillaris") can be found. There are also scrub plants including Hawthorn ("Crataegus monogyna"), Mountain ash ("Sorbus aucuparia"), gorse ("Ulex europaeus") and Elder ("Sambucus nigra"). Several of the caves support bat populations. Geologically it is recognised as a fluvial karst feature which partly intersects a buried and filled