Betula pendula subsp. szechuanica, the Sichuan birch or Szechuan birch, is a birch subspecies native to southeastern Tibet, Gansu, Qinghai, Sichuan, and northern Yunnan in western China. It is conical in shape, growing to 20 meters in height, with white bark, yellow-green male catkins or green female catkins, and dark, blue-green leaves.
References
GBIF entry Alison Hoblyn and Marie O'Hara, Green Flowers: Unexpected Beauty for the Garden, Container Or Vase, page 40, Timber Press, 2009. .