Food safety around plants develops from recognizing that some parts of otherwise familiar species can contain natural chemicals that harm people. Multiple sources note that green potatoes and rhubarb leaves are examples of foods that appear edible but can be dangerous. Green potatoes contain toxins linked to exposure of the tuber to light, and rhubarb leaves contain chemical compounds that can make humans sick, even though rhubarb stems are commonly eaten. The shared message is that plant edibility is not determined only by appearance or by belonging to a known plant, but also by which specific part is consumed. Over time, learning about plant safety comes from knowledge of plant chemistry, observation of illness, and research that identifies toxic compounds and explains why certain plant components cause harm. As a result, guidance emerges for which plant parts to avoid and which parts are safe, such as warning people not to eat green portions of potatoes and not to consume rhubarb leaves.