The buds located at the nodes on a plants stem, if "activated," will
produce more stems...right? Usually, this is the casestem tissue begets stem tissue,
root tissue begets root tissue. But of course its never that neat and tidy! Think back to that section of ivy vine sitting in a jar of water.
When we "root" a cutting like that, were hoping that root tissue will form
along the submerged stem. And remember our example of the violet plant? When sprouts form
at nodes along the creeping stems, both shoots and roots are produced on stem tissue.
Botanists have a term for this phenomenon. Roots that
arise from stem (or any other non-root) tissue are called adventitious roots. Adventitious shoots, you
might guess, are shoots arising from non-stem tissue, usually roots.
Now lets look at some asexual means of propagation,
and see where adventitious roots and shoots play a role.