Description from Flora of China
Trees or sometimes shrubs, evergreen or deciduous. Trunk bark deeply splitting or exfoliating longitudinally. Winter buds ovoid-globose, ovoid-conical, or rarely ovoid-ellipsoid; scales few to many, imbricate. Leaves spirally arranged. Stipules extrapetiolar. Male inflorescence pendulous, solitary in leaf axils toward base of branchlets or in paniculate clusters on lateral or subterminal shoots; flower solitary and scattered on rachis; perianth calyciform, 4-7-lobed or more lobed; stamens 4-7 or fewer, filaments slender; staminodes small. Female inflorescences in leaf axils toward apex of branchlets, with few to many cupules; flowers solitary; perianth 5- or 6-lobed; staminodes sometimes present, small; ovary (2-or)3(or 4)-loculed; stigmas dilated or ligulate, lining inner faces of styles. Cupules solitary; bracts imbricate, scalelike, linear, or conical, adherent, prostrate, or reflexed. Nut 1 per cupule. Germination hypogeal.
About 300 species: N Africa, Asia, Europe, North America, South America (Colombia); 35 species (15 endemic, two introduced) in China.
After this treatment was published for the FOC, it came to our attention that Craibiodendron forrestii W. W. Smith (Notes Roy. Bot. Gard. Edinburgh 5: 160. 1912), described from W Yunnan (Nujiang valley), is a species of Quercus (see FOC 14: 459. 2005).