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
Root invasion Root invasion Root invasion is the incursion of plant roots with undesirable impacts. When the roots of neighboring plants or trees invade the area of other plants there will be decline in the health and eventual wasting of the plant whose space is being invaded. In planted areas, periodical inspection during planting and care can allow for the discovery and removal of invading roots. As plant roots spread in the search for nutrition, they will opportunistically enter irrigation or sewer with resulting line blockage. 5% of sewer line blockage is attributed to root invasion, though reports of line breakage due