The oldest tree in the world is the colony called Pando, sharing one underground root system. It is a grove of trees located in Fishlake National Forest, Utah in the United States. Its age is estimated at over 80,000 years. Pando has been able to survive that long by cloning and growing new trees that are part of the grove. Old trees are replaced with new ones, but the root system is still shared.
Another very old tree is Old Tjikko, discovered in 2008 in Sweden. Its age is estimated at 9550 years. Although it is a single tree, it also survived through cloning although it is not a colony of trees like Pando. Unlike Pando, Old Tjikko regenerated its branches and roots in the same place. Old Tjikko’s root system is approximately 10,000 years old, while its individual branches usually live for 600 years and new ones grow in their place.
The „Unnamed Great Basin Bristlecone Pine” was believed to be the oldest single tree in the world. Its age is estimated at 5062 years. It was estimated in 2010 by Tom Harlan and in 2012 the nameless, large pine was officially recognized as the oldest tree in the world. Unfortunately, in 2017, this status was revoked because Tom Harlan’s core samples could not be found. Thus, it was not possible to confirm the age.
Until 2012, the oldest known tree in the world was Methuselah („Methuselah”) growing in Inyo County, California. Its age is estimated at 4,850 years. Methuselah was discovered in 1957 by Tom Harlan. According to calculations, this tree germinated around 2832 BC, which makes it older than the Egyptian pyramids.