The Manchineel tree, native to the Western Hemisphere, is the most poisonous tree in the world. The tree is poisonous on so many levels that if you ever spot one, it is better you stay at least a few yards away from it.
Its fruit resembles a small apple, but eating one could land you right in the emergency room. The manchineel’s milky white sap is incredibly caustic and poisonous as well – even a drop could cause skin blisters, dermatitis, swelling or burns. The sap is so caustic that even the rain drops coming from the branches can cause burns. The bark is poisonous too – burning it releases a smoke that causes temporary (and in some cases, permanent) blindness.