Black turmeric is a rare herb. It is the underground portion of the stem, or rhizome, of the Cucurma caesia plant. The plant itself is sometimes grown as an ornamental, but the root has been used for centuries for medicinal and religious purposes. Black turmeric offers benefits similar to the orange variety, but the darker cultivar contains higher concentrations of curcumin than any other Curcuma species. In Hindi, the herb is called Kali Haldi.