Via Modern Farmer:  ‘Visit the remote mountainside towns in Turkey’s Black Sea region during springtime and you may witness beekeepers hauling their hives upslope, until they reach vast fields of cream and magenta rhododendron flowers. Here, they unleash their bees, which pollinate the blossoms and make a kind of honey from them so potent, it’s been used as a weapon of war.

The dark, reddish, “mad honey,” known as deli bal in Turkey, contains an ingredient from rhododendron nectar called grayanotoxin — a natural neurotoxin that, even in small quantities, brings on light-headedness and sometimes, hallucinations. In the 1700s, the Black Sea region traded this potent produce with Europe, where the honey was infused with drinks to give boozers a greater high than alcohol could deliver.

When over-imbibed, however, the honey can cause low blood pressure and irregularities in the heartbeat that bring on nausea, numbness, blurred vision, fainting, potent hallucinations, seizures, and even death, in rare cases. Nowadays, cases of mad honey poisoning crop up every few years—oftentimes in travelers who have visited Turkey.’ (thanks to Boing Boing)