Imagine if all it took to replace a lost leg was to put another leg against the amputation site, tie up the wound and let the two grow together. We can do that with plants! We’ve been doing it for thousands of years and it is an important part of crops production for woody plants (think fruit trees).
The technique is called grafting and it really is almost that simple. A branch or stalk* from one plant is cut and attached to another plant of the same or a related species**, making sure to line up the vascular tissue*** of the cut branch and host plant. That connection is covered with grafting wax or grafting compound which keeps the exposed ends of the cuts from drying out which would stress or kill the cells.