The Trembling Giant

Pando (Latin for "spread out"), also known as the Trembling Giant, is a clonal colony of an individual male quaking aspen (Populus tremuloides) determined to be a single living organism by identical genetic markers and assumed to have one massive underground root system. The plant occupies 43 hectares (106 acres) and is estimated to weigh collectively 6,000,000 kilograms (6,600 short tons), making it the heaviest known organism. The root system of Pando, at an estimated 80,000 years old, is among the oldest known living organisms.

Pando is located 1 mile (1.6 km) southwest of Fish Lake on Utah State Route 25, in the Fremont River Ranger District of the Fishlake National Forest, at the western edge of the Colorado Plateau in south-central Utah, United States.

The clone now known as Pando was discovered in 1968 by researcher Burton V. Barnes, who continued to study it through the 1970s. Barnes had described Pando as a single organism based on its morphological characteristics alone; molecular techniques and methods developed since that time have largely substantiated those conclusions. Building on Barnes's earlier work, Michael Grant of the University of Colorado at Boulder re-examined the clone, named it "Pando", and claimed it to be the world's most massive organism in 1992. In 2006 the United States Postal Service published a stamp in commemoration of the aspen, calling it one of the forty "Wonders of America."