Aspen has distinctive, almost-circular leaves with flattened petioles or stems. This flattening causes the leaves to tremble or flutter in the slightest breeze, thereby giving the tree one of its ...

DENVER (KDVR) — Each fall, Colorado proves to ... the U.S. Travel + Leisure named Aspen among the best places in the country for views of the colorful fall leaves this year.

Populus tremuloides, the quaking aspen of the North ... to the ‘fixed’ leaves was, on average, about 27% higher in the stabilized members of the pairs. This tree species seems to almost ...