The oak family comprises five genera and 375 species. The family is of wide geographical distribution, and from an economic point of view, of very great value. Four genera occur in the United States, namely, Fagus (the Beech), Castanea (the Chestnut), Quercus (the Oak), and Castanopsis. The number of species and varieties recognized is 87. Of this number 82 belong to the genus Quercus, one each to Fagus and Castanopsis, and three to Castanea. The only genus indigenous to Iowa is Quercus, the oak, and the number of species recognized is 15
