Backstone Bank and Baal Hill Woods one side valley, there is a small population of small-leaved lime, "Tilia cordata", which occurs here close to its northern limit and at an unusually high altitude. On base-rich soils, the woodland typically consists of ash, "Fraxinus excelsior", and wych elm, "Ulmus glabra", over an understorey of hazel, "Corylus avellana", and bird cherry, "Prunus padus", and a rich ground flora that includes lady-fern, "Athyrium filix-femina", male fern, "Dryopteris filix-mas", and hard shield-fern, "Polystichum aculeatum". On more acid soils, sessile oak, "Quercus petraea", and birch, "Betula sp.", are dominant. The under-storey, of hazel, holly, "Ilex aquifolium", rowan, "Sorbus aucuparia", and hawthorn,
Sorbus chamaemespilus in corymbs 3–4 cm diameter. The fruit is an oval red pome 10–13 mm diameter. It is the sole species in a group that has been called genus "Chamaemespilus" or "Sorbus" subgenus "Chamaemespilus", distinguished from other subgenera of "Sorbus" by the pink (not white) flowers with forward-pointing petals (not opening flat). More recently, it has become clear that the simple-leafed species traditionally included in "Sorbus" form a monophyletic group, and this species could be included in a clade called "Aria" (genus "Aria" or "Sorbus" subgenus "Aria"). Sorbus chamaemespilus Sorbus chamaemespilus, the false medlar or dwarf whitebeam, is a species of