Was warned today about the dreaded jumping cholla, a hostile species that apparently waits patiently and then jumps and snags onto ambulatory life forms passing nearby for transportation. Nice strategy for getting around. Scary, like the odd critters in the Aussie outback trying to kill you.
Checking on the web, they don't quite have the ability to jump at you, but they do have tenacious micro spines that embed into virtually anything.
Photo By Nebarnix, CCSA 3.0
Add to that a wobbly stem structure, you get a an ouch when the first one digs in, a pull back reaction which bends the whole plant like a golf shaft and lofts more of these hostile balls of microspines at you. Ouch. Process repeats, and repeats. Before you know it, the legend of the attacking jumping cholla is perpetuated (Golf Fan Attacked by Jumping Cactus on the Tube here).
They're nasty and painful, and best to avoid them, but leave 'em alone untouched, and you'll be fine. And if you do get pricked, don't react, scream and hop around cuz they will "jump" on you :-)
(via Jiro on iPhone)