Cacti, cacti, and more cacti

I was in Arizona a few weeks ago to visit my good friends J. Paul and Judy Fennell. I did some botanizing and had some fun playing with wood. This post shows a series of photos featuring different species of cacti. I wasn't interested in getting the whole plant in the frame, but wanted to explore the textural contrasts the spines have against the stems. I don't know the names of these different cacti, either. Some of the pictures were taken on the Fennell property in Scottsdale, and the rest at the Desert Botanical Garden in Phoenix.