General Sherman, thx .. hello there .. look at us .. Largest girth?
The giant sequoia is also not the tree with the largest girth (thickest giant sequoia: 8.98 m diameter, Boole Tree). Some African baobabs (Adansonia digitata), see the image on the right, have similar girths at the end of the wet season. During the heavy rainfall of the wet season, these trees try to store as much water as possible in their thick trunks to survive the hot dry season so their girth changes constantly during the year.
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If you take trees with multiple stems into account, there is a thicker Montezuma cypress (Taxodium mucronatum). A strangely shaped specimen, the famous árbol del Tule in Mexico, has a "diameter" of 11.42 m (image on the left).
Oldest tree in the world?
The giant sequoia definately is one of the species that can become very old, but it has to leave the first place to the bristlecone pine (Pinus longaeva), a small Californian type of pine (4000 to 5000 years) and the south American alerce, Fitzroya cupressoides.
The oldest Pinus longaeva of which the age was determined exactly based on tree ring countings, was 4844 years old in 1965 (the tree was cut).
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The images above show such pines. They grow at high altitudes in quite poor conditions, so these tough trees grow rather slowly and are gnarly and weathered. The oldest living Pinus longaeva is about 4789 years old and is the world's oldest tree.
Take a moment to think about how old this is. America was not yet discovered, there was no christianity or islam. Rome and Athens were not founded yet, even the piramids in Egypt were not yet built when this tree was already growing and was facing all weather.
Then the Western men comes and cuts them down. Such a lack of respect, that's just beyond my comprehension.
Comes in second on the list of old trees: Fitzroya cupressoides. The age of a certain specimen in Chile appeared to be 3622 years old in 1993.
The giant sequoia comes in third: a specimen was 3266 years old when it was cut.