Betula utilis to overuse of the tree for firewood. "Betula utilis" was described and named by botanist David Don in his "Prodromus Florae Nepalensis" (1825), from specimens collected by Nathaniel Wallich in Nepal in 1820. "Betula jacquemontii" (Spach), first described and named in 1841, was later found to be a variety of "B. utilis", and is now "Betula utilis" var. "jacquemontii". In its native habitat, "B. utilis" tends to form forests, growing as a shrub or tree reaching up to tall. It frequently grows among scattered conifers, with an undergrowth of shrubs that typically includes evergreen "Rhododendron". The tree depends on moisture
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