Pando, the world's largest tree, is a quaking aspen tree located in Sevier County, Utah in the Fishlake National Forest. A male clonal organism, Pando has an estimated 47,000 stems (ramets) that appear as individual trees, but are connected by a root system that spans 106 acres. Pando is the largest tree by weight and landmass and, is the largest known aspen clone. Pando was identified as a single living organism because each of its stems possesses identical genetic markers. The massive interconnected root system coordinates energy production, defense and regeneration across its expanse. Pando spans 0.63 miles by 0.43 miles of the southwestern edge of the Fishlake Basin in the Fremont River Ranger District of the Fishlake National Forest and lies 0.43 miles to the west of Fish Lake, the largest natural mountain freshwater lake in Utah. Pando is located at an elevation of 2,700 m (8,900 ft) above sea level.

Populus tremuloides is a deciduous tree native to cooler areas of North America, one of several species referred to by the common name aspen. It is commonly called quaking aspen, trembling aspen, American aspen, mountain or golden aspen, trembling poplar, white poplar, and popple, as well as others. The trees have tall trunks, up to 25 metres tall, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden to yellow, rarely red, in autumn. The species often propagates through its roots to form large clonal groves originating from a shared root system. These roots are not rhizomes, as new growth develops from adventitious buds on the parent root system.