Many eucalypts shed their bark very year, but on an Ironbark the dead bark stays on the trees, forming the furrows. It becomes rough after drying out and becomes full of kino, a dark red tree sap exuded by the tree. The bark is resistant to fire and heat and protects the living tissue within the trunk and branches from fire. In cases of extreme fire, where leaves and shoots are removed, the bark protects the epicormic buds which allow the tree to reshoot.