=Charlock.= _Brassica arvensis_ (L.) B. S. P. Pods tipped with a flattened elongated-conic, often 1-seeded beak. See also cuts of rutabaga and black mustard. Introduced from Europe. See statements last above.
=Rutabaga.= _Brassica campestris_ L. Seed dull, light or dark reddish brown, roughened by an indistinct net work of ridges, very nearly spherical, 1.4-1.8 mm. in diameter. Much cultivated, inclined to escape. Included here for comparison with other species. Introduced from Europe.
=Indian Mustard.= _Brassica juncea_ (L.) Cossos. See also cuts of turnip and black mustard. Introduced from Europe.
=Black Mustard.= _Brassica nigra_ (L.) Koch. Seeds dark brown to reddish brown, 1-1.7 mm., spherical, or broadly oblong, not flattened. The surface of well developed specimens presents a delicate but evident net work of fine ridges which appear under the lens as dark lines. The scar (hilum) is a whitish, elevated spot, at one extremity of the oblong seeds. See cuts of seeds of turnip. Introduced from Europe. A vigorous persistent weed.
=Small Fruited False-Flax.= _Camelina microcarpa_ Andrz. Flowers small, yellow; pods pear-shaped, flattened, about 6 mm. long, surrounded by a vertical ridge; seeds reddish brown, granular, usually broad-oval, about 1 mm. long, slightly flattened, the vertical ridge much less prominent than in C. sativa. When wet the seed is soon covered with mucilage. Not yet very common. Naturalized from Europe.
=False Flax.= _Camelina saliva_ (L.) Crantz. The common name is derived from the fact that it is a weed of flax fields in Europe. Flowers small, yellowish; pods pear-shaped, slightly flattened, 8-10 mm. long, surrounded by a vertical ridge. Seeds reddish yellow, granular, usually oval, 2-3 mm. long, one side flat or roundish, the other furnished with a prominent vertical or oblique ridge. Seed incumbent. When wet the seed is soon covered with mucilage. Naturalized from Europe.
=Shepherd's Purse.= _Capsella Bursa-pastoris_ (L.) Medic. _Bursa Bursa-pastoris_ (L.) Britton. Flowers small, white; pods flat, nearly triangular, about 4 mm. long. Seeds reddish yellow, granular, oblong, slightly flattened, 1 mm. or less long. Each side usually bearing two longitudinal grooves, separating the surface into three nearly equal parts, these grooves indicating the position of the parts of the embryo. When placed in water, a copious coat of transparent mucilage appears on the surface. In Nevada and Colorado a great pest in fields of Alfalfa.