Cultivated throughout China. The leaves are salted for food; the seeds and the whole herb are used for medicine, which can dissolve phlegm, calm asthma, reduce swelling and relieve pain; the seeds are ground into powder and called mustard, which is used as a seasoning; the oil squeezed out is called mustard oil; this species is an excellent honey plant.
Europe and the United States are rarely cultivated, originated in Asia. Li Shizhen's "Compendium of Materia Medica" recorded the medical value of medical mustard.
Morphological features
Annual herb, 30-150 cm high, often glabrous, sometimes young stems and leaves with prickly hairs, frosty, spicy flavor; stems erect, branched.
Basal leaves broadly ovate to obovate, 15-35 cm long, rounded at the tip, cuneate at the base, lyrate, with 2-3 pairs of lobes, or undivided, margins notched or dentate, petiole 3-9 cm long, with lobules; lower stem leaves smaller, margins notched or dentate, sometimes crenellated serrate, not embracing the stem; upper stem leaves narrow lanceolate, 2.5-5 cm long, 4-9 mm wide margins obscurely sparsely dentate or entire.
Racemes terminal, prolonged after flowering; flowers yellow, 7-10 mm in diameter; pedicels 4-9 mm long; sepals yellowish, oblong-elliptic, 4-5 mm long, erectly spreading; petals obovate, 8-10 mm long, 4-5 mm long. Long-horned fruit linear, 3-5.5 cm long, 2-3.5 mm wide, petals with 1 prominent midvein; beak 6-12 mm long; fruiting pedicel 5-15 mm long. Seeds globose, ca. 1 mm in diam. Fl. March-May, fr. May-June.