Stenocereus griseus grafting stock with some aerole grafts, upside down bottom end grafts, etc.
Astrophytum asterias
As you can probably tell from the picture... and the grafts being done... I'm attempting to select an all orange specimen that will give me orange Astrophytum pups as opposed to the variegated form. Grafting is an excellent means of selecting out clonal varieties from specimens showing altered tissue growth characteristics such as variegation.