Common madder is an evergreen perennial plant. The plant is native to Southeastern Europe, Western Asia, and North Africa, but was early on introduced to the Central and Northwestern Europe where it became naturalized. This plant has small yellow flowers with 5 petals. The size of the flowers is only 3 to 5 mm. Leaves are 5 to 10 cm long and 2 to 3 cm broad. The roots are over 1 meter long and about 12 mm in diameter. They are used to make a red dye for textiles. Common madder can be 1 to 1.5 meter tall. The roots are harvested and used to produce red dyes for textiles. This dye has also been used sometimes in paints. The plant has also been used for medicinal reasons. The roots contain the acid ruberthyrin. By drying, fermenting or a treatment with acids, this is changed to sugar, alizarin and purpurin. Purpurin is normally not coloured, but is red when dissolved in alcalic solutions. Mixed with clay and treated with alum and ammonia, it gives a brilliant red colourant (madder lake). Iran, Turkey, India and China are the producers of common madder.