Figure 115.White mustard (Brassica alba)
Sinapis alba L.
Yellow mustard, charlock, kedlock, senvre.
White mustard is a weed found in cultivated fields and waste places, but it is not so abundant nor so widely distributed as the black mustard. It is cultivated on a commercial scale in California.
The white mustard grows from 1 to 2 feet in height. It is more or less hairy, with stiff, spreading hairs. The lower leaves, which are 6 to 8 inches in length, are deeply lobed, but the upper ones are lance shaped. The surface of the leaves is rough hairy. The light yellow flowers are borne in clusters at the ends of the stems from about June to September. The narrow, spreading seed pods which follow are rough hairy, contracted between seeds, and are about an inch in length, containing numerous roundish, pale-yellow seeds.
The seed, the pods being collected when they are nearly ripe but not ready to burst open. After drying, the seed may be readily threshed or shaken out.