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
Alnus viridis Alnus viridis Alnus viridis (green alder) is an alder distributed widely across the cooler parts of the Northern Hemisphere. It is a large shrub or small tree 3–12 m tall with smooth grey bark even in old age. The leaves are shiny green with light green undersurfaces, ovoid, 3–8 cm long and 2–6 cm broad. The flowers are catkins, appearing late in spring after the leaves emerge (unlike other alders which flower before leafing out); the male catkins are pendulous, 4–8 cm long, the female catkins 1 cm long and 0.7 cm broad when mature in late autumn, in clusters