Leaves are probably the most common feature used to identify trees. But in winter, when so many trees have dropped their ...

However, almost all mature American elm trees have been killed in the last 50 years by Dutch elm disease, which is caused by a fungus, Ophiostoma novo-ulmi, introduced from Asia. Elm bark beetles ...

There are simple ways to identify these trees. The base of elm trees ... This disease is caused by an invasive fungi pathogen and spread by elm bark beetles, and it has been deadly for elm ...