I would tend to agree with the licking. I've noticed that years that we've had bad thistle (tumbleweeds) the bellies always tend to be a bit darker. I hadn't pout a lot of thought into it until reading HG's response. I reckon I'd be licking myself too if I was having to wander around in that stuff all summer. 22 Chuck, exactly what you said. Just one of Mother natures cruel tricks!
If God wanted us to be vegetarians, he would have made broccoli more fun to shoot at!