Language: Spanish
Volume 28 covers the Fagaceae, which contains 9 genera and some 600-800 species worldwide. In Mexico, this family is represented by the genera Castanea, Fagus, and Quercus, the latter being the most speciose with some 200 species. Of those, 22 species in the genus Quercus are found in the Tehuacán–Cuicatlán Valley of central Mexico.