Turmeric

Turmeric is in the ginger family. Its rhizomes are the source of a bright yellow spice and dye.
A botanical painting of a turmeric stem with rhizomes.
Spice mix
Turmeric is a main ingredient of curry powder. The rhizomes are cooked, dried and then ground to produce the strongly coloured, aromatic powder.
A domesticated plant
Turmeric is only known as a domesticated plant and not found in the wild. It originated from South and Southeast Asia, and may have been first used as a dye before it became a popular spice.
Dyes
As well as being a culinary spice, turmeric is a well known dye plant in South Asia. Its colour varies depending on how it is processed. If mixed with alkaline fluids it turns bright red, but when mixed with acid it produces yellow.
Anti-ageing
Turmeric has traditionally been used to counteract many conditions including the ageing process in Ayurvedic medicine.