A red dye extracted from roots of several different plants. A major source of East Asian madder is the perennial vine with wholes of four leaves and small white flowers, Rubia cordifolia L. The purpurin and alizarin in the roots produce the red dye. Native Japanese madder, Rubia akane is distinct in that it does not contain alizarin and its red color’s characteristic compound is six-hydoroxyrubiadin, which is also the most prevalent compound among the madders found on red silks and paper in the Shōsō-in. Rubia tinctorum (seiyō akane or “Western madder”) contains the most alizarin and is found in wool rugs in the Shōsō-in.