Plants don’t hiss, chase, or bare teeth, which is why people tend to underestimate them. Yet some of the most efficient poisons ever encountered by humans come not from animals or laboratories, but from leaves, seeds, roots, and sap. Long before chemistry had names for toxins, people were already learning—often fatally—that certain plants could shut down the heart, destroy the nervous system, or slowly poison the body beyond recovery.

Be careful what you touch, and be just as cautious about what you eat. Nature does not announce its dangers in advance, and some plants can end a human life just as effectively as a venomous animal. Across the world, hundreds—possibly thousands—of plant species contain toxic compounds capable of harming or killing people. Most trigger irritation or illness, but a small number are genuinely lethal, even in very small amounts.

Mushrooms occupy a strange place in human culture. They are celebrated as delicacies in countless cuisines, prized for their earthy flavors and nutritional value, yet feared for their ability to cause sudden and devastating harm. For centuries, people have relied on mushrooms for food, medicine, and ritual, while at the same time passing down warnings about which varieties must never be eaten. That tension between nourishment and danger still exists today, especially for anyone who encounters wild mushrooms outside of controlled farming environments.