Field Mustard.Brassica Sinapistrum.Charlock.Crowd Weed (W. Va.).
Found in grain fields, and along cultivated lands, from July to September.
The large and branching stalk is zigzag or curved in habit of growth, about 2 or 3 feet high, and ribbed; with occasional hairs; it is bright green in color.
The lower leaves are lyre-shaped and large, the middle lobe wide and curving to a long pointed tip, the side lobes being narrow; the upper leaves are irregularly cut; the margins are notched (the points of the notches often turn toward the stem), the edge curling or wavy; the midribs and netted veins often pucker the surface, which is shining; the color is a clear full green. They are set on short stems, or clasp the stalk, and are alternately arranged.
The flower has 4 shell-shaped petals, with very long and erect bases, of a fine texture, and yellow color with a tinge of green; the calyx is 4-divided, its parts slender and wide-spreading, also yellow but with a marked tendency to green. The flowers form close leafy terminal clusters.
As the petals fall early and only two or three flowers are open at once, the seed-pods, green and shining, form a distinctive feature of the plant; when they ripen, and in their turn drop, their little foot-stems are left bristling along the elongating branch. The leaf suggests Gothic ornament with its quaint curves and lines.