The grove is called Pando, which is Latin for “I spread” — and spread it does. The grove is actually a single clonal colony of a male Quaking Aspen. Simply put, it is essentially one massive root system that began life an estimated 80,000 years ago. The root system currently has somewhere around 47,000 stems that create the grove of trees that keep the root system going.
Pando is not only considered the oldest living organism but also possibly the heaviest. The colony has spread over about 106 acres and experts think in all it weighs about 6,600 short tons. However, some experts think that chunks of the root system have died off leaving parts of the colony separated, making it effectively more than one organism. And other less-studied clonal colonies of aspen may be contenders for the title of heaviest.
Pando exists in part because frequent fires have kept conifers out of the area, and because a shift to a semi-arid climate has kept other aspen seedlings from taking root. This has left plenty of space for the ancient root system of Pando to spread and thrive. The fact that Pando is one giant organism wasn’t discovered until the 1970s, by Burton V. Barnes of the University of Michigan. Currently, experts are worried that a range of factors are threatening the life of this ancient organism. source