[bloak]

See https://en.wikipedia.org/wiki/List_of_longest-living_organis...

I've not yet seen an explanation of what counts as a single "organism" for these purposes and the estimated ages are all over the place.

[Buttons840]

My guess at a definition: All parts connected, having the same DNA, and supporting each other by sharing nutrients.

[ebolyen]

This is true of corals, and they are often considered "colonial" organisms instead of an individual.

That said, I don't think anyone who studies biology is particularly concerned with hard-line definitions, as nature tends to eschew them every chance it has.

I think Pando and corals being considered "modular bodyplans/habits" is perhaps a more useful concept than individual or clone.