Agaves (Agave sp.) are succulents found throughout the southwest, Mexico and South America and are probably best-known as the plants from which tequila is made. But they have another legacy, says botanist Wendy Hodgson. Her studies suggest that these plants were cultivated for food and other uses by pre-Columbian farmers in present-day Arizona, as far back as 900AD. Take a trip to the desert north of Phoenix to see where these ancient strains of agave are still growing.