Description from Flora of China
Trees or rarely shrubs, monoecious, evergreen or deciduous. Stipules usually early deciduous. Leaves alternate, sometimes false-whorled in Cyclobalanopsis. Inflorescences unisexual or androgynous with female cupules at the base of an otherwise male inflorescence. Male inflorescences a pendulous head or erect or pendulous catkin, sometimes branched; flowers in dense cymules. Male flower: sepals 4-6(-9), scalelike, connate or distinct; petals absent; filaments filiform; anthers dorsifixed or versatile, opening by longitudinal slits; with or without a rudimentary pistil. Female inflorescences of 1-7 or more flowers subtended individually or collectively by a cupule formed from numerous fused bracts, arranged individually or in small groups along an axis or at base of an androgynous inflorescence or on a separate axis. Female flower: perianth 1-7 or more; pistil 1; ovary inferior, 3-6(-9)-loculed; style and carpels as many as locules; placentation axile; ovules 2 per locule. Fruit a nut. Seed usually solitary by abortion (but may be more than 1 in Castanea, Castanopsis, Fagus, and Formanodendron), without endosperm; embryo large.
Seven to 12 genera (depending on interpretation) and 900-1000 species: worldwide except for tropical and S Africa; seven genera and 294 species (163 endemic, at least three introduced) in China.
Many species are important timber trees. Nuts of Fagus, Castanea, and of most Castanopsis species are edible, and oil is extracted from nuts of Fagus. Nuts of most species of this family contain copious amounts of water soluble tannin. Members of the Fagaceae are the main element of both broad-leaved evergreen and mixed mesophytic forests from 500-3200 m.
Huang Chengchiu, Chang Yongtian, Hsu Yongchun & Jen Hsienwei. 1998. Fagaceae. In: Chun Woonyong & Huang Chengchiu, eds. Fl. Reipubl. Popularis Sin. 22: 1-332.
(Authors: Huang Chengjiu (黄成就 Huang Ching-chieu) , Zhang Yongtian (张永田 Chang Yong-tian) ; Bruce Bartholo)