Kalonji seeds are the small black granules found in the fruits of Nigella sativa plant which is an annual herbaceous plant which belongs to the Ranunculaceae family. This is native plant of south west Asia that is abundantly cultivated in India, Bangladesh, Turkey and other Eastern countries.

The plant has erect stem, light green finely divided leaves, blue and white star shaped flowers and fruits bearing black seeds. These are usually triangular, tiny and hairy seeds of no more than 3mm in length and possess a severe pungent smell.