Cyclobalanopsis

Cyclobalanopsis is a group of evergreen oaks in the beech family Fagaceae. In many classifications it is recognized as a distinct genus Cyclobalanopsis, but most modern treatments place Cyclobalanopsis as a section or subgenus within Quercus, the genus that includes all oaks. When recognized as a separate genus, Cyclobalanopsis comprises Asian evergreen oaks distinguished by cupules whose scales form concentric rings around the acorn, giving the characteristic ring-cupped appearance.

Leaves are simple and alternately arranged, generally evergreen and leathery, with margins that range from entire to finely serrate. The fruit is an acorn that matures in one growing season, often partially enclosed by a ringed cupule.

Geographic range covers much of eastern and southeastern Asia, including parts of China, Japan, Korea, and Indochina. Habitat includes temperate to subtropical forest communities, frequently in montane regions, where these oaks contribute to forest structure and biodiversity.

Taxonomic status remains debated: some checklists and flora treat Cyclobalanopsis as an independent genus, while others place its species in Quercus, sect. Cyclobalanopsis. The group is broadly recognized for its distinctive acorn cupules and evergreen habit, setting it apart from many northern oaks.

Ecologically, acorns provide food for various birds and mammals, and the wood is used locally for timber and ornamentally in appropriate climates. The taxonomy and species delimitation within Cyclobalanopsis continue to be refined as part of broader studies of Fagaceae diversity.