Methuselah (California, USA)
A Great Basin bristlecone pine estimated, based on tree-ring analysis, to be more than about 4,800 years old. Named after the longest-lived figure in the Bible, its exact location is kept secret to prevent vandalism or damage. It has long been cited as one of the oldest individual trees known to science.
An unnamed bristlecone pine
A bristlecone pine possibly even older than Methuselah has reportedly been surveyed in the same region, but its location remains undisclosed and its exact age continues to be debated. Handled with great caution even within the scientific community due to how sensitive the information is, it is a fascinating example showing that there is no single, settled answer to the question of exactly which tree is the oldest on Earth.
Old Tjikko (Sweden)
A Norway spruce whose visible above-ground trunk is only a few hundred years old, but whose root system is estimated to have been alive continuously for about 9,500 years. In the harsh environment, when the above-ground trunk dies, a new trunk repeatedly sprouts from the roots — making it unique in that only the root system has survived continuously since just after the last ice age. It is a leading example of why the "age of the trunk" and the "age of the organism (the roots)" must be considered separately.
Pando (Utah, USA)
A famous case in which what appears to be tens of thousands of individual quaking aspen trees was found to actually be a single organism connected by one shared root system. Individual trunks are short-lived and constantly sprout anew, but estimates of the age of the organism as a whole vary enormously among researchers, ranging from thousands to tens of thousands of years. By weight, it is also introduced as one of the heaviest living organisms on Earth.
Jōmon Sugi (Yakushima, Japan)
A Japanese cedar on the island of Yakushima in Japan, with an estimated age that varies enormously among researchers, from around 2,000 to 7,000 years — a leading example of this kind of debate. Precise age measurement is difficult because the tree's interior is hollow, making it impossible to count its tree rings in full. Nevertheless, it has long been considered sacred in Japan and remains a popular destination for many hikers today.
General Sherman Tree (Sequoia National Park, USA)
A giant sequoia that, while not as old as the bristlecone pines (estimated at roughly 2,000 years), is known as the largest single tree on Earth by volume. It is a good example of how "the oldest tree" and "the largest tree" are two entirely different records. As the tree symbolizing Sequoia National Park, it draws large numbers of tourists every year.