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
Pterocarya fraxinifolia appear in April, the male catkins thick and green, 7.5 – 12.5 cm long, the females longer with less dense flowers, bearing red styles forming fruiting catkins 30 – 50 cm long, the green, winged, nuts approximately 1.8 cm wide. The species is fast growing and grows best on flat ground or shallow slopes near river banks and in deep moist soils. The climate associated with the distribution of this tree includes mild winters and mild humid summers. It generally grows in mixed stands with other species and rarely grows in pure stands. Fossils of "Pterocarya fraxinifolia" have been described