The highly poisonous tree tobacco is native to Bolivia and Argentina, but it has naturalized elsewhere, including Hawaii, southern USA and the Mediterranean. Cal Lemke's Plant of the Week highlighted Nicotiana glauca 6.5 (!) years ago, so do visit PotW for more info.
On another topic, I mentioned the Festival of the Trees blog carnival a few weeks ago. I submitted this BPotD entry on Thuja plicata for yesterday's festival, and it made it in. Go check it out: Festival of the Trees 6 at Arboreality. Be warned: there are a lot of fine links in this edition, and you'll find your weekend slipping away.