What you would see in Medieval England were trees introduced during the Bronze Age and the Roman conquests, in addition to some native species. You would find elm, willow, walnut, aspen, sweet chestnut, beech, hornbeam, whitebeam, poplars, rowan, silver birch, field maple, beech, alder, ash, hazel, and perhaps most surprisingly, lime trees. There were almost no evergreens. The only species you might see would be juniper, scotch pine, yew, and evergreen holly—if you choose to classify the large variety of holly as a tree.