Betula lenta as long as the tree lives, but the individual bark layers become indiscernible after roughly 250 years of age. "Betula lenta" was used commercially in the past for production of oil of wintergreen before modern industrial synthesis of the oil; the tree's name reflects the wintergreen scent of the shoots. The sap flows about a month later than maple sap, and much faster. The trees can be tapped in a similar fashion, but must be gathered about three times more often. Birch sap can be boiled the same as maple sap, but its syrup is stronger (like molasses). The leaves
Betula utilis from snowmelt, rather than from the monsoon rains. They often have very bent growth due to the pressure of the deep winter snow in the Himalaya. Leaves are ovate, long, with serrated margins, and slightly hairy. Flowering occurs from May–July, with only a few male catkins, and short, single (sometimes paired) female catkins. The perianth has four parts in male flowers, and is absent in the female flowers. Fruits ripen in September–October. The thin, papery bark is very shiny, reddish brown, reddish white, or white, with horizontal lenticels. The bark peels off in broad, horizontal belts, making it very usable