Description from Flora of China
Trees, sometimes shrubs, deciduous; bark fissured or smooth. Stipules deciduous. Leaves alternate, irregularly and doubly or simply serrate. Male inflorescence pendulous, spicate-cymose, cylindric, enclosed by buds during winter, with many overlapping bracts; flowers without bracteoles or perianth; stamens 3-12, inserted at base of bracts; filaments forked at apex; anthers 2-loculed, thecae separate, pubescent at apex. Female inflorescence terminal or axillary on dwarf shoots, racemose; flowers paired; bracts leaflike, complanate, overlapping, 2- or 3-lobed at base. Nutlet ribbed, enclosed by lobes of bracts or not.
About 50 species: China, India, Japan, Korea, Laos, Myanmar, Nepal, Thailand, Vietnam; Europe, North and South America; 33 species (27 endemic) in China.
Because of inadequate material, Carpinus fargesiana has not been included in the key.