I live in Abu Dhabi but go to Dubai every month or so for some courses and I spotted this beauty in the landscaping - please note the soda can at the bottom for scale....
Now THAT is a Desert Rose!! I've seen some that have naturalized and are fairly large, like Hetty said they seem about half to a quarter that size. But that is one that looks so natural and seems to be the way they were intended to look. It's beautiful!