Salvia Divinorum

Sign offering Salvia Divinorum for sale at a booth at the Willie Street Fair in Madison, Wisconsin, 2007.

Salvia Divinorum is an intense psychodelic causing users to experience strong hallucinations. The substance hasn't yet been banned by government officials in many places, so it's perfectly legal for sale. At the moment.

The Willie Street Fair is set in a neighborhood which has very strong hippie roots and liberal sympathies, so this sort of booth sign (along with overt drug use) is generally expected at this festival.