There are evergreen trees that get very large. There are those that are up to 90 m high in Tasmania. Typically, the outermost cortical layer falls off in long strips. They are mainly grown because they grow very quickly and they are good usable wood for the paper and furniture industries. There is an abundant essential oil in the leaves, which is used as a medicine. Every 10 years, the crown of the tree gets cut and that happens four times until the tree is cut down. The roots of these trees penetrate deep into the soil; this can dry it out and so alter natural habitats. In addition, they burn very quickly. That is why they are not well seen in the Algarve, because of the forest fires that often occur during the summer.