Edible sweet chestnut (Castanea sativa) is easily distinguished from toxic horse chestnut (Aesculus hippocastanum), aka conker, as the casing or ‘cupule’ is covered with flexible spines that are quite different from the conker’s spines. The sweet chestnuts found on the woodland floor contain two or three nuts, unlike the single large nut associated with commercially grown cultivars.
photo: © Jack Brodie