Sorbus or uncertain parentage, have gained the Royal Horticultural Society’s Award of Garden Merit: Sorbus Sorbus is a genus of about 100–200 species of trees and shrubs in the rose family, Rosaceae. Species of "Sorbus" ("s.l.") are commonly known as whitebeam, rowan, service tree, and mountain-ash. The exact number of species is disputed depending on the circumscription of the genus, and also due to the number of apomictic microspecies, which some treat as distinct species, but others group in a smaller number of variable species. Recent treatments treat "Sorbus" in a narrower sense to include only the pinnate leaved species of
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