Hippomane mancinella
EXTREMELY TOXIC. Do not touch any part of this tree. The sap causes severe chemical burns. Standing under it in rain can burn skin. The fruit (which looks like a small green apple) can be fatal if eaten. One of the most dangerous trees in the world. Observe from a safe distance only.
The most dangerous tree in the Western Hemisphere — and it grows right here on Miami Beach. Every part of the manchineel is toxic: the sap burns skin on contact, the fruit can kill, and even standing under it in the rain is dangerous because water dripping through the leaves carries the toxic sap. It's important to know this tree exists so you can teach others to avoid it.
Rare on Miami Beach itself, but present in natural areas along Biscayne Bay and in the Keys. Usually marked with warning signs or red paint on the trunk. Fairchild Tropical Botanic Garden has labeled specimens for safe observation.
Despite being dangerous to humans, manchineel is an important native coastal species. Its dense wood resists hurricane damage. The fruit is eaten by iguanas and certain crabs that are immune to the toxin. It provides shore stabilization in natural coastal areas. It's protected under Florida law.
Spanish conquistadors called it 'arbol de la muerte' (tree of death). When Columbus's men first arrived in the Caribbean, they ate the fruit and wrote that it tasted sweet at first, then their throats swelled shut. The Carib people used the sap to poison arrows and reportedly tied captives to the tree during rainstorms as a form of torture.
Learn to identify manchineel from a safe distance. This is a critical survival skill for anyone living in or visiting South Florida. The tree that looks most inviting (shady, with apple-like fruit) is the most dangerous.
Photos of manchineel (or safe distance observation of a labeled specimen)