Tomatoes, along with red peppers, are members of the Nightshade Family, and are native American plants. The English word tomato is derived from the Spanish word tomate, which comes from the Nahuatl word tomatl. Nahuatl is the language of the ancient Aztecs, who controlled central Mexico upon the arrival of the Spanish. Montezuma spoke Nahuatl.
Confusingly for English speakers, in central and part of southern Mexico the Spanish word tomate refers not to our familiar red tomato, but rather to what in English is called the husk-tomato, ground-cherry, or tomatillo; it's Physalis ixocarpa, shown at the right. The item we Northerners call tomato, Lycopersicon esculentum, in those pparts is called jitomate. In other parts of Mexico red tomatoes may be referred to as tomates.
Often the husk-tomato's husk is removed and then the small, green or maybe purplish fruit inside the husk is sold as tomate verde, or "green tomato." Tomate verde is used in making salsa verde, or green sauce, while jitomate makes salsa roja, or red sauce.