| | AllRefer.com - root, in botany (Botany, General) - Encyclopedia (Site not responding. Last check: 2007-10-16) |
 | | root, in botany, the descending axis of a plant, as contrasted with the stem, the ascending axis. |
 | | Root systems often far exceed in mass the aboveground portions of the plant: alfalfa roots sometimes reach 40 ft (12 m) in length, and the combined length of all the roots of a mature rye plant has been measured at 380 mi (612 km). |
 | | In the center of the root the cells formed earlier by the embryonic cells of this layer differentiate into storage tissue and xylem and phloem vessels to conduct sap upward to the leaves and back down to nourish the root cells. |
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