Oak wilt is a deadly disease that affects all species of oaks (Quercus) found in Minnesota. It is caused by a non-native, invasive fungus (Bretziella fagacearum, formerly Ceratocystis fagacearum). The fungus invades the water-conducting vessels of oaks, eventually killing infected trees. While the oak wilt pathogen can infect all species of oak, those in the red oak group (leaves with pointed lobes) die about two months after infections. Bur oaks die between one and seven years after infection, while white oaks die from one to over 20 years after infection.