The most widely distributed tree in North America, famous for its shimmering golden autumn groves and for forming the largest clonal organism on Earth.
Where it grows
Quaking aspen ranges from Alaska across Canada and the northern United States, south through the Rocky Mountains into northern Mexico. It tolerates a wider range of climates than any other North American tree, growing from sea level to over 3,000 metres elevation.
How to recognise it
Smooth, whitish-greenish bark with prominent dark scars at the base of branches. The round, fine-toothed leaves hang on flat petioles that twist and quake in the lightest breeze — the diagnostic feature of the species. Autumn colour is among the most spectacular in North America, with whole hillsides of the Rocky Mountains turning electric gold.
Uses
Aspen wood is light, weak, and prone to decay, but its abundance and fast growth make it the dominant pulp and oriented strand board (OSB) species across Canada. Wildlife use of aspen is enormous — beavers fell them for dam-building, elk and moose browse the saplings.
Pando
A single male quaking aspen clone in Fishlake National Forest, Utah, called Pando, covers 43 hectares and contains 47,000 stems all sharing one root system. By dry mass it is the heaviest single organism known to science, and may be tens of thousands of years old.