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 aucuparia tart, and aromatic, and candied or used in compote. The two cultivars are self-pollinating, yield fruit early, and the sugar content increases while the acid content decreases as the fruit ripen. 'Beissneri' is a cultivar with reddish foliage and bark and serrated leaves. Other edible varieties originate in and are named after Klosterneuburg, Lower Austria. Russian botanist Ivan Vladimirovich Michurin began in 1905 to crossbreed common "S. aucuparia" with other species to create fruit trees. His experiments resulted in the cultivars 'Burka', 'Likjornaja', 'Dessertnaja', 'Granatnaja', 'Rubinovaja', and 'Titan'. Other "S. aucuparia" hybrids planted in Western Europe beginning in the 1980s