From my Sedona AZ P&S experience.
"right after this pick"
See that spiky thing on my hand? Well I'm not holding it, this attacking Cacti decided to imbed itself in my hand. I'm not smilin either, I'm cursing through my teeth.
Rob and I wanted to get an image of us in front of a Cactus. Well his elbow brushed up against another one, and then it all went downhill from there. Since this thing was so spiky (and sharp) I used 2 rocks to see if I could smack it off Rob's elbow. Well, half came off, and imbedded in my hand. Immediatly, I backed up into another one which imbedded into my leg. We were like the 2 stooges. Anyways, bloodied and 20min later, we decided that we were already late, so skip the emergency room and off to Sedona.