Eucalyptus trees are highly flammable.That oil permeates the wood and will go up in a second when lit. On the Berkeley campus there is a grove of eucalyptus and to smells just like a bag of Halls cough drops. In the open spaces around the SF bay area, they planted lots of eucalyptus in the late 19th century. Now they are clearing them out because they are a fire danger and are not native.