Belgium | 1951 | 1 Franc | Flora & Fauna | Oak
Belgium Oak Oak refers to trees or shrubs in the genus Quercus of the beech family ( Fagaceae ), comprising about 600 species. Native to the Northern Hemisphere, oaks include both deciduous and evergreen types, ranging from temperate to tropical regions. North America has the highest diversity, especially the United States and Mexico, while China is the second major center of species diversity. Oaks typically have spirally arranged leaves, often lobed or serrated. They produce male catkins and small female flowers on the same tree. Their fruit is an acorn—a single-seeded nut held in a cup-like cupule—that matures in 6–18 months. Some species, such as live oaks, are evergreen, though they are not a separate distinct group within the genus.