Betula grossa long, yellow-brown, male catkins in early spring. . The species is considered closely related to the American birch "Betula lenta". Hardiness: RHS H4. Betula grossa Betula grossa, commonly known as Japanese cherry birch, is a species of birch native to Japan, where it grows naturally in mixed woodland on hill and mountain slopes in Honshu, Shikoku , and Kyushu. It was introduced to the West in 1896, but remains rare in cultivation. "Betula grossa" is conical in outline, but its most distinctive feature is its cherry-like bark, with horizontal stripes of reddish-grey becoming dark grey with age, exfoliating in thin
Betula lenta male catkins pendulous, the female catkins erect. The fruit, maturing in fall, is composed of numerous tiny winged seeds packed between the catkin bracts. Seed production mainly occurs in trees that are between 40 and 200 years old, although light crops may occur as early as 15 years and as long as the tree lives. Contrary to common knowledge, the lifespan of "B. lenta" is typically around 200 years, and many individuals will reach 250 and even 300 years. The oldest known "B. lenta" has been confirmed to be 368 years old, and the species may live even longer than