This enables the tree to absorb a small amount of ... In North America, the closely related quaking aspen (Populus tremuloides) is found in much of Canada and the northern USA.

Quaking aspens store chlorophyll beneath their bark (particularly in younger trees), this is what gives the trunk a greenish cast. This helps them to continue to produce sugars, at least when the days ...

these two species occupy the broadest range of any tree species in the world. Why is that so? Quaking aspen can be found from Alaska to Mexico and from Vancouver to Maine (Jones et al. 1985 ...