[ETL]

This 9,550-year-old Spruce tree is the oldest single tree in the world. It is located on Fulufjället Mountain in Sweden. The tree was discovered by Lief Kullman, a professor at Umeå University, who nicknamed it Old Tjikko, after his late dog. Read more: http://www.businessinsider.com/arbor-day-the-oldest-known-tree-on-earth-2014-4#ixzz3brydJOBO

http://www.businessinsider.com/arbor-day-the-oldest-known-tree-on-earth-2014-4

[ETL]

Pando, an 80,000-year-old colony of
quaking aspen, is the oldest known
clonal tree, located in Utah, United States

http://en.wikipedia.org/wiki/List_of_oldest_trees

[Inyo-Mono]

Not entirely true, from the article:

Tjikko has stayed alive for so long because of a process called "vegetative cloning." When the trunk of Old Tjikko dies, the root system stays alive and sprouts a new trunk. Most trunks of the tree live for hundreds of years.

The oldest single living trees (original trunk) in the World are to be found in the Bristlecone Pine Forest in the White Mountains of California. From Wikipedia:

The Methuselah Grove in the Ancient Bristlecone Pine Forest is the location of the "Methuselah", a Great Basin Bristlecone Pine that is 4,846 years old.[5] For many years, it was the world's oldest known living non-clonal organism, until superseded by the discovery in 2013 of another bristlecone pine in the same area with an age of 5,064 years (germination in 3051 BC).[6] "Methuselah" is not marked in the forest, to ensure added protection from vandals.

[Spruce]

A fine tree, indeed.

[SunkenCiv]

Thanks ETL and Inyo-Mono. Near the onetime geographical center of the Sahara there was a living olive tree. Didn't look all that vivacious, but was still alive. And it's a cultivated species.