Epicormic shoots on the trunk of a horse chestnut tree (Aesculus hippocastanum). The trunk of an aged horse chestnut tree, with signs of damage from earlier in its life. Below centre and to top are two holes in the trunk; positions from which a limb has been lost, possibly due to storm damage or rot. The trunk shows scattered outgrowths (bosses) that are producing short shoots, emerging through disorganised bark. These are known as epicormic shoots. They develop from normally dormant buds beneath the bark. The triggers for growth of epicormic shoots are thought variously to be mechanical damage, infection or insect attack. Many trees can develop epicormic shoots; the most commonly seen are found on lime trees (Tilia spp). In public parks, such an effect can be triggered at ground level by damage from grass mowers striking the base of the tree.