Cruciferae Brassica juncea (L). Coss., B. japonica Sieb., B. campestris L.
Source: Magness et al. 1971
These, and possibly other species of Brassica, are grown under the name mustard for the young green leaves which are used as pot herbs or "greens." All are annuals grown from seed, and form clusters of leaves, the edible portion, prior to forming a seed stalk. Leaves are rather large, with blades 6 inches or more in length, smooth or curled or notched, somewhat pubescent when young, later glabrous. They are harvested early, while the leaves are tender. Culture and exposure of leaves are comparable to spinach. The condiment "mustard" is the ground seed of another species.
Production in U.S.: 9,493 acres reported in 1959 census, possibly 20,000 tons.
Use: Fresh, canned, frozen for pot herbs and to limited extent in salads.
Part of plant consumed: Leaves, including stems.