What root or flower that can make purple dye?

The root of the madder plant (Rubia tinctorum) can be used to produce a purple dye, known for its vibrant color and historical significance in textile dyeing. Additionally, the flower of the indigo plant (Indigofera) can yield a blue dye that, when combined with other natural substances, can create purple hues. Another source is the purple flower of the woad plant (Isatis tinctoria), which also contributes to dyeing processes.