50. Manchineel Trees

Manchineel trees might look fairly innocuous, but don’t take that as a sign to get up close and personal with them. As Britannica noted, parts of the Floridian tree are loaded with a harmful toxin named phorbol. It’ll hurt your skin in an instant. Oh, and try not to take shelter under its branches when it rains. The compound can mix with the water and hit you with some painful drips. Ouch!