Just like a pack of cigarettes, the manchineel tree comes with a health warning: "This tree is very TOXIC," reads a sign that adorns one specimen of the tropical plant, which grows in south Florida, South and Central America, and a few other locales. Just looking at the tree, though, you'd never suspect it's the most deadly in the US. Atlas Obscura describes it as a "pleasant-looking beachy sort of tree, often laden with small greenish-yellow fruits that look not unlike apples." It is ill advised, however, to sample the fruit. “Shipwrecked sailors have been reported to have eaten manchineel fruits and … they had inflammations and blistering around the mouth," says botanist Roger Hammer. "Other people have been diagnosed with severe stomach and intestinal issues." That's why, per Mother Nature News, the tree has been dubbed by some as manzanita de la muerte—the "little apple of death."
In an account about eating a so-called "beach apple," radiologist Nicola Strickland says the fruit was "pleasantly sweet," but then a "burning, tearing sensation, and tightness of the throat" set in. The "excruciating pain" lasted for hours, she writes. And it's not just the fruit. According to Guinness World Records, which lists the manchineel as the "most dangerous tree," its sap can cause burning and blindness, even when diluted by rainwater. Smoke from the burning wood also can cause blindness. But the manchineel, which also grows in the Caribbean, Central America, and northern South America, does have some redeeming attributes, per Atlas Obscura. The wood, when harvested and dried properly, is great for cabinetry and other uses. And, notes MNN, the bark can be used to treat edema and may hold the key to scientific breakthroughs. (Trees need their sleep, too.)