High Quality Content by WIKIPEDIA articles! Nigella sativa is an annual flowering plant, native to south and southwest Asia. It grows to 20–30 cm (7.9–12 in) tall, with finely divided, linear (but not thread-like) leaves. The flowers are delicate, and usually coloured pale blue and white, with five to ten petals. The fruit is a large and inflated capsule composed of three to seven united follicles, each containing numerous seeds. The seed is used as a spice.