Salicaceae Populus spp.
All species look alike microscopically.
The word populus is the classical Latin name for the poplar tree. Quaking aspen ranges from Alaska through Canada and into the northeastern and western United States. In North America, it occurs as far south as central Mexico at elevations where moisture is adequate and summers are sufficiently cool. The more restricted range of bigtooth aspen includes southern Canada and the northern United States, from the Atlantic coast west to the prairie. Most aspen stands are a mosaic of several clones.