Root plant to fuel the process. In return, the plant takes nitrogen compounds produced from ammonia by the bacteria. The term root crops refers to any edible underground plant structure, but many root crops are actually stems, such as potato tubers. Edible roots include cassava, sweet potato, beet, carrot, rutabaga, turnip, parsnip, radish, yam and horseradish. Spices obtained from roots include sassafras, angelica, sarsaparilla and licorice. Sugar beet is an important source of sugar. Yam roots are a source of estrogen compounds used in birth control pills. The fish poison and insecticide rotenone is obtained from roots of "Lonchocarpus" spp. Important
Sweet potato Sweet potato The sweet potato ("Ipomoea batatas") is a dicotyledonous plant that belongs to the bindweed or morning glory family, Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are a root vegetable. The young leaves and shoots are sometimes eaten as greens. The sweet potato is only distantly related to the potato ("Solanum tuberosum") and does not belong to the nightshade family, Solanaceae, but both families belong to the same taxonomic order, the Solanales. The plant is a herbaceous perennial vine, bearing alternate heart-shaped or palmately lobed leaves and medium-sized sympetalous flowers. The edible tuberous root is long and tapered, with