These thorns may not look menacing but believe me when I say you don't ever want to brush up against them. They sting and leave their marks- I have proof after backing into this one several times this past week.
Ouch. One year i was photographing a cactus in Hawaii carefully (I thought) keeping my distance...a while later when we had walked a couple miles further away from where we were staying, my back started hurting. I asked Jim to give it a look and he found millions of spines. We went home and googled what to do...didn’t even have any tweezers with us. Saved by elmers glue1