I agree with Karen! There are almost no photos of Discocactus in the database. They make me appreciate how difficult it must be for a taxonomist! These photos remind me of Echinocactus texensis which is native here. It's no wonder they are always revising the plant families!
I didn't realize Brazil had any arid terrain, so I looked it up and found the sertao region of north east Brazil. How cool is that? I would never have thought Tucson had any common climate with any place in Brazil except for temperature. So I learned a bit from your posting already.
