Quercus (genus) en

Genus containing around 450 species of ornamental and timber trees and shrubs, found chiefly in north temperate regions and at high altitudes in the tropics. The durable wood has a distinctive coarse grain. The thick bark from some species is used for its buoyancy. Tannins and dyes can be extracted from the bark. Oak emits organic acids as it ages. Many plants commonly called "oak" are not Quercus, including African oak, Australian oak, bull oak, etc.