This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Deciduous small trees. Perianth none. Male flowers in lateral drooping catkins, with 6 to 12 stamens in the axils of the ovate acute bracts. Female flowers in terminal pendulous bracteate catkins, 2 at the base of each deciduous bract; brac-teoles lobed. Fruit 1-celled, 1-seeded, somewhat woody, strongly nerved, enclosed in the enlarged lobed bracteole. Four species are known, all natives of the north temperate zone. The name is of classical origin.
1. C. Betulus. Hornbeam. - A small indigenous tree resembling the Beech in foliage, but readily distinguished by the opaque not shining doubly serrate leaves, simply pubescent not silky, hairy below, and the winged fruit. Indigenous in the South of England.