I know, I was surprised, Kathleen, in this little book alone, there are about 5 or 6 samples of different Prickly Pear varieties. I always admire people who have all these species memorized, in fact, I've heard you discuss various plants and trees here - you kind of amaze me, but I'm botanically ignorant.
I'm trying to learn a little more because I do like to photograph plants, buds and flowers. I should be able to call them something other than "plant" or "flower" LOL...