A member of the spurge family, the world´s most dangerous tree is the manchineel (Hippomane mancinella) of the Florida Everglades and the Caribbean coast. The sap that its trunk exudes is so poisonous and acidic that the merest contact with human skin causes a breakout of blisters, and blindness can occur if it touches a person´s eyes. Even standing under it in the rain is enough to cause blistering if the skin is wetted by raindrops containing any sap. In addition, a single bite of its small green apple-like fruit causes blistering and severe pain, and can prove fatal. And if one of these deadly trees is burned, the resulting smoke can cause blindness if it reaches a person´s eyes.
Comments below may relate to previous holders of this record.