I have heard that there is no limit on the growth of trees, but
then why do some trees, such as boxelders and poplars, tend to
live shorter than redwoods, for example? Some advertisements for
improved lombardy poplars state that their trees have an
extended life span, up to 75 years? Although most plants can
potentially reproduce sexually, there are some plants that
effectively always reproduce by shedding off branches that when
fall in the right conditions, grow into new 'clones' of the same
tree, which the exact genetic material. In these cases, it is
advantageous for the tree to be able to survive as long as
possible. Plants that reproduce sexually by the cross of two
different individuals have a recombined genetic material in
every generation, and the survival of that plant with that new
genome is usually shorter.