Roots and Tubers
Root crops are an important but poorly understood group of food plants. There are three main groups: the yams (Dioscoreaceae), the edible aroids (Araceae), and potatoes (Solanaceae). Most root crops originated either in high, arid areas such as the Andes, where the tubers allow the plant to survive through difﬁcult winter conditions, or in the tropical forest, where tuber plants are adapted to long dry seasons and quickly mature at the onset of the rainy season. Root crops are particularly important in areas that are too high or too wet for seed crops.