There is a "weed" called "plaintain that grows in most unsprayed lawns and vacant lots.* As a kid, you probably shot the little dried flower heads in the air for fun. One indian name for it is "white man's footprint" because it quickly appears wherever soil has been disturbed. It is GREAT for stings. I got chin-stung last week on a ride, pulled the bike over to the first lawn I passed, pulled a leaf, chewed it a bit, and rubbed it on the sting. The sting ebbed and was a minor itch in minutes. If I can find a good picture, I'll post it.

*Hmm, I'm talking about the east coast. Don't know about the deserts, etc.