Weed question- smell and burning?

Question

I was pulling weeds behind our garage yesterday and when I pulled one it let off a horrible smell. I understand the smell as a defense to keep animals away- but my skin started burning through my gloves. Any idea what kind of weed this is?

Answer 1

Does it look like this?  It could be ironically-named Tree of heaven

http://forums.gardenweb.com/forums/weeds...