There are 300 kinds of selected trees. According to relevant data, the selected trees are also called Lithocarpus, which is the general name of evergreen trees of Lithocarpus in FAGACEAE. Fruit is also called acorn. The fruit is blue when it is young and dark brown when it is mature. There are 300 species in the world, except for the west of North America 1 species, the rest are all produced in Asia, mainly distributed in the south and southeast of Asia, about 30 degrees north latitude and 0/0 degrees south latitude.