Possible Clues:

• Hallucinogen-yielding cactus
• Desert hallucinogen
• Hallucinogenic cactus
• Mescaline-yielding cactus
• Mescaline source
• Cactus drug
• Mexican cactus
• Narc's find, maybe
• Cactus also called mescal
• Shaman's hallucinogen