Agricultural weeds are currently a leading cause of crop losses. A weedy type of rice (Oryza sativa) invades cultivated rice fields worldwide. The three sample weeds shown here were collected from a single rice field in eastern Spain. Using population genetic approaches, the Caicedo lab seeks to understand the origin of weedy rice and of its morphological diversity. Understanding the processes that shape weed evolution may lead to development of new management practices that decrease the impact of weeds on agricultural production.