This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Brassica alba, Boiss (Sinapis alba, L.)
Introduced. Annual or biennial. Propagates by seeds.
Time of bloom: June to August.
Seed-time: July to September.
Range: Locally in most parts of North America except the far
North. Habitat: Cultivated ground, waste places.
Fig. 129. - Indian Mustard (Brassica juncea). X 1/4.
As a weed, this plant is usually the survival of dormant seeds from former cultivation, or an escape, though its seeds are occasionally found with those of other plants.
Stems one to two feet high, branching, covered with stiff, spreading hairs. Lower leaves with slender petioles, deeply pin-natifid, the terminal lobe very large, the lateral lobes small and narrow, all toothed and rough-hairy; upper leaves less divided, with shorter petioles or the topmost ones sessile. Flowers yellow, more than a half-inch broad, the sepals spreading and much shorter than the petals. Siliques round and very bristly, the beak often longer than the part containing the seeds. Seeds light yellow, smooth, larger than those of Black Mustard, milder in flavor. (Fig. 130.)
Means of control the same as for Charlock and Black Mustard.