Which is the world's oldest known living individual tree species by clone?

Definitions of longevity vary between clonal trees, ones where parts of the tree continue to live after the death of the first trunk or trunks, and non-clonal trees. Tree ages are derived from a variety of sources, including documented "tree-ring" (dendrochronological) count core samples, radiocarbon dating, girth-to-age formulas, and estimates from growth rates. For these reasons, there are three lists of "oldest trees" here, using different criteria.