Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Stem plants that get too tall can be trimmed off and the tops replanted. The bottom is often bare or has just a few leaves, but will often sprout new branches at the point it was cut.
After a while the older parts don't have too much recovery, but by then you have several 'generations' of cuttings going. You can pull out the non-productive ones and replant with some of the new trimmings.
Since this is a form of clonal reproduction, I think it also counts as a long life of a single plant. No flowers or seeds are involved, not a real next generation.