Like all species of Quercus, those of subgenus Cerris are trees or shrubs with acorn-like fruit in which a cup covers at least the base of the nut.

The structure of the mature pollen is one feature that distinguishes the two subgenera: in subgenus Cerris, the small folds or wrinkles (rugulae) are visible or at most weakly obscured, whereas in subgenus Quercus, the rugulae are obscured by sporopollenin.

Like all species of Quercus, those of section Cyclobalanopsis are trees or shrubs with acorn-like fruit.

The 'cup' (cupule) around the base of acorn also has distinct rings formed from thin membranes (lamellae), which also distinguishes the section from other oaks.

[1] The section contains about 90 species native to tropical and subtropical Asia including the southern Himalayas.

[1] Like all species of Quercus, those of section Ilex are trees or shrubs with acorn-like fruit.

[1] Quercus section Cerris was first established by Barthélemy Charles Joseph Dumortier in 1829.

[1] Like all species of Quercus, those of section Cerris are trees or shrubs with acorn-like fruit.

The ornamentation of the mature pollen is distinctive, consisting of scattered small bumps (verrucate).

The cup of the acorn has narrowly triangular scales, thickened and with a keel and elongated recurved tips.

[5] The 2020 Red List of Oaks shows that within the species assessed across all eight sections of the genus Quercus, the sections Cyclobalanopsis and Ilex have the largest proportions of species put into the "critically endangered" category, representing the highest level of threat.