Turmeric (Curcuma longa) is a rhizomatous herbaceous perennial plant of the ginger family, Zingiberaceae. It is native to tropical South Asia and needs temperatures between 20 °C and 30 °C (68 °F and 86 °F) and a considerable amount of annual rainfall to thrive. Plants are gathered annually for their rhizomes, and propagated from some of those rhizomes in the following season.

When not used fresh, the rhizomes are boiled for several hours and then dried in hot ovens, after which they are ground into a deep orange-yellow powder commonly used as a spice in curries and other South Asian and Middle Eastern cuisine, for dyeing, and to impart color to mustard condiments. Its active ingredient is curcumin and it has a distinctly earthy, slightly bitter, slightly hot peppery flavor and a mustardy smell.

In medieval Europe, turmeric became known as Indian saffron, since it was widely used as an alternative to the far more expensive saffron spice.

Nizamabad, a city in the south Indian state of Andhra pradesh, is the world's largest producer and most important trading center of turmeric in Asia. For these reasons, Nizamabad in history is also known as "Turmeric City".^{[citation needed]} Sangli, a town in the southern part of the Indian western state of Maharashtra, is the second largest and most important trading center for turmeric in Asia. Kasur district of Pakistan is the largest producer of turmeric in Pakistan. Mayo cultivators introduced different varieties of turmeric in Kasur. Turmeric is commonly called Pasupu in Telugu, Kaha (කහ) in Sinhala, Manjal (மஞ்சள் ) in Tamil, Arisina (ಅರಿಸಿಣ) in Kannada, Haridra (हरिद्र) in Sanskrit and Haldar or Haldi (हल्दी) in Hindi. Attempts to patent turmeric have been defeated.