Oaks are hardwood trees in the faminy Fagaceae, the Beech family. Oaks are angiosperms, meaning they have flowers. (although they are small and green) Some oaks are evergreen... for instance california live oaks.. there are also oaks in rain forests and various other areas.. almost all are in the northern hemisphere. Oaks are important parts of many plant communities, and often assist in the survival of other native plants. In some areas, factors such as grazing and fire suppression are repressing oak germination, and research is currently being done to address this problem