Ulmus microcarpa

Ulmus microcarpa was named and first described by the Chinese botanist L. K. Fu, who discovered the tree in the Chayu broad-leaved forests of south-eastern Xizang at altitudes of around 2800 m during the 1973 Qinghai - Tibet Expedition. Unlike the majority of Tibet, the Chayu region has a subtropical highland climate featuring warm, wet, summers and mild, dry, winters (avg. annual rainfall 807 mm). Commonly known as the Tibetan Elm, the tree was introduced to the United States in 2006, and the UK in 2013; it remains one of the rarest species of elm in cultivation....read more on Wikipedia.