Tobacco, potatoes, chili peppers, tomatillos, and tomatoes are all members of the nightshade family. All of these plants bear such resemblance to the European nightshade that even an amateur could deduce that they were a kind of nightshade, just by simple observation of the flowers and berries. Similar to some European Nightshade varieties, tomatoes and potatoes can be harmful or even lethal, if the wrong part of the plant is consumed in the wrong quantity. Physicians, in the 16th-century, had good reason to be wary that this native Mexican fruit was poisonous; they suspected it of generating "melancholic humours".