Monoecious, evergreen or deciduous trees, rarely shrubs. Leaves are usually toothed or lobed, stipulate. Male flowers in catkins, solitary or in clusters on them. Perianth campanulate or cupular, 3-6-lobed; stamens usually 6, pistillode sometimes present. Female flowers solitary or in clusters of 3 on erect spikes; perianth surrounded by an involucre of scales; ovary 3-5-locular; styles usually as many as the loculi. The fruit partially enclosed in a cupule formed by the accrescent and hardened involucral scales; seed solitary, rarely more.
Distribution and Ecology:
Widely spread over Diamer District at an elevation range of 994 m to 2300 m. Over 400 species are distributed in America, temperate Europe, Asia, and sub-tropical Africa. Represented here by 6 species.