Genus Rubia is a group of flowering plants that belong to the Rubiaceae family. This genus is commonly known by its popular name, madder, due to its deep red roots that are used for dyeing fabric and for medicinal purposes. Some synonyms for the Genus Rubia include Rubiacea, Krappia, and Galium. Krappia is a synonym that is used in the taxonomy of flowering plants, whereas Galium was once grouped under the genus Rubia, but it has since been reclassified. Regardless of the name, these plants are known for their bright red roots, which have been used for centuries to create dyes and for medicinal purposes.