Betula glandulosa to tall, often forming dense thickets. The trunks are slender, rarely over diameter, with smooth, dark brown bark. The leaves are nearly circular to oval, long and broad, with a toothed margin. The fruiting catkins are erect, long and broad. It is closely related to the dwarf birch ("Betula nana"), and is sometimes treated as a subspecies of it, as "B. nana" subsp. "glandulosa". It is distinguished from typical "B. nana" by the presence of glandular warts on the shoots and longer leaf petioles. Hybrids with several other birches occur. Betula glandulosa Betula glandulosa, the American dwarf birch, also known
Betula lenta vertical cracks into irregular scaly plates revealing rough dark brown bark patterns. This, however, only occurs in mature, or ancient, trees and these specimens are not often identified by the public as "B. lenta" due to the difference between the tree's smooth young bark (which the public is most familiar with) and the tree's rough, cracked and plated mature bark. The twigs, when scraped, have a strong scent of wintergreen due to methyl salicylate, which is produced in the bark. The leaves are alternate, ovate, long and broad, with a finely serrated margin. The flowers are wind-pollinated catkins long, the