Madder, Rubia tinctorum, is a plant of the family N.O. Rubiaceae also known as krapp, dyer's madder and robbia. Native to most of Europe, including southern Britain, and Mediterranean countries, the stalks of the Madder are so weak that they often lie along the ground, preventing the plant from rising to its maximum height of 8 feet. The stalks are prickly, and the whorls of leaves at the joints have spines along the midrib on the underside, a feature that has been used by the French for polishing metal-work. The herb is also used as fodder for animals.
The best European Madder is Dutch, but the plant native to Smyrna is said to be even finer. The Turkey-red and other shades are adjective dyes, different mordants bringing many shades of red, pink, lilac, purple, brown, orange and black.
During the nineteenth century, a very popular red dye was extracted from the madder plant and this was used to dye British soldiers' coats their characteristic red. The active compound in madder, alizarin, was first synthesised in 1869 but was soon superseded by William Perkin's synthetic aniline dyes. As a consequence of this, the madder industry collapsed across Asia and southern Europe in the 1870s, leading to widespread unemployment and poverty.
As a dye it colours milk, urine and bones, so that experiments in the growth of bones can be conducted with its help. Rubia tinctoria differs only slightly from the Wild Madder or R. peregrina, and so may not in fact be a separate species.