Radix rubiae, the Madder Root plant or Asian Madder, has a long history as a dye plant. It’s native to East Asia – China, Japan, Korea. (In Korea it’s also used as a medicinal herb.) Note that this species of madder plant is different from the European Rubia tinctorum, but closely related.
In China, Madder Root was the main red dye as early as the Shang and Zhou dynasties. Silk dyed with madder can turn a very beautiful red color, which has been recorded in many historical documents. Science Direct tells us that “The madder root produces an array of fast colors, ranging from pale pinks and violets, through deep reds to oranges and browns. It is considered significant as a dye source because red dyes are difficult to achieve both from natural and synthetic sources, and as such madder is considered a valuable source of natural reds. “