Brassica nigra

Mustard, black mustard

Family: Cruciferae

The annual black mustard can grow 2m / 6 ½ ft high with bristly lobed leaves. Yellow flowers are followed by smooth, erect seed pods. Probably originally from the Middle East, it is widely cultivated. Sow the dark, round seeds in a sunny position in rich soil in spring and harvest just before the pods open in late summer. Dry the seeds in their pods.

The seeds are hotter and more pungent than those of white mustard, and contain an acrid oil and sulphur (which discolours silver spoons). It is stimulant, irritant and emetic – a tablespoon of mustard flour in lukewarm water provokes vomiting. Used as a poultice the oil draws blood to the surface of the skin, thus soothing the part. Make this by mixing 25g/ 1oz mustard flour and 25g / 1oz bran to a paste with hot water; it can also be applied to the chest for bronchitis. Pour hot water over bruised seeds to make a soothing bath for tired feet.