Madders refer to substances derived from the roots of the madder plant that are commonly used to produce red dyes. There are several synonyms that can be used to refer to these substances including rubia, alizarin, and morinda. Rubia is derived from the Latin name of the madder plant while alizarin is the name of the primary dye compound found in the roots. Morinda is also a synonym commonly used in the Pacific Islands where the morinda tree is found and its roots are used as a dye source. There are also several related terms such as madder lake and madder root that refer specifically to different parts of the plant or the dyes they produce.