Birch leaves are the foliage of the birch tree, a common tree found in many temperate regions. These leaves are typically oval or triangular in shape, with serrated edges. They are bright green in spring and summer, turning yellow in the fall. The leaves grow alternately on the branches and can be up to 3 inches long. The leaves play a crucial role in the tree's life cycle, as they are responsible for photosynthesis, the process by which the tree converts sunlight into energy. Additionally, birch leaves are known for their medicinal properties and are sometimes used in herbal remedies.