Turmeric or tumeric (Curcuma longa) /ˈtərmərɪk/ or /ˈtjuːmərɪk/ or /ˈtuːmərɪk/ is a rhizomatous herbaceous perennial plant of the ginger family, Zingiberaceae. It is native to southern Asia, requiring temperatures between 20 and 30 °C (68 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 about 30–45 minutes and then dried in hot ovens, after which they are ground into a deep-orange-yellow powder commonly used as a spice in Bangladeshi cuisine, Indian cuisine, Iranian cuisine, Pakistani cuisine and curries, for dyeing, and to impart color to mustard condiments.

Source: Wikipedia