...from my time spent in Tucson, last spring and summer, is this cactus in bloom. I ran across this one on a rock outcrop on the Super Trail at Madera Canyon. Click on it to enlarge, the flower is pretty awesome as far as flowers go. It has always amazed me how plants can grow right out of cracks in bare rock but that is just what this one did; I suppose getting nourishment from whatever debris gets caught in the same crack and eventually decomposes to form a bit of soil for the cactus. If anyone knows what it is, please leave the name in a comment. Thanks.
All the best,