(Linnaeus) Czernajew, Consp. Pl. Charcov. 8. 1859.
Chinese or brown or Indian or leaf mustard, mustard-greens
Linnaeus, Sp. Pl. 2: 668. 1753;
(Thunberg) Siebold ex Miquel;
L. H. Bailey;
(Thunberg) L. H. Bailey
(± glaucous), ± glabrous.
branched distally, 2-10 dm.
(early deciduous); petiole (1-)2-8(-15) cm; blade pinnatifid to pinnately lobed, (4-)6-30(-80) cm × 15-150(-280) mm, lobes 1-3 each side.
usually shortly petiolate, rarely sessile; blade (oblong or lanceolate, reduced in size distally), base tapered or cuneate, not auriculate or amplexicaul, (margins dentate to lobed).
not paniculately branched.
spreading to divaricately ascending, (slender), (5-)10-15(-20) mm.
sepals (3.5-)4-6(-7) × 1-1.7 mm; petals pale yellow, ovate to obovate, (7-)9-13 × 5-7.5 mm, claw 3-6 mm, apex rounded or emarginate; filaments 4-7 mm; anthers 1.5-2 mm.
(sessile); spreading to divaricately ascending to nearly erect (not appressed to rachis), torulose, subcylindrical or somewhat flattened, (2-)3-5(-6) cm × 2-5 mm; valvular segment with 6-15(-20) seeds per locule, (1.5-)2-4.5 cm, terminal segment seedless (conic), (4-)5-10(-15) mm, (tapering to slender style).
brown or yellow, 1.2-2 mm diam.; seed coat finely reticulate-alveolate, not mucilaginous when wetted.
Flowering May-Sep. Roadsides, disturbed areas, waste places, cultivated and abandoned fields, garden escape from cultivation; 0-3000 m; introduced; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask.; Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; Asia; Africa; introduced also in Mexico, West Indies, Central America, South America, Australia.
is cultivated in North America primarily as a vegetable and condiment, and is currently being developed as an oilseed crop in western Canada. Its greatest diversity of forms occurs in Asia, where the species is widely cultivated as a vegetable and as an oilseed crop (I. A. Al-Shehbaz 1985). Two main variants are distinguished on the basis of seed color: oriental mustard is yellow-seeded, and brown or Indian mustard is brown-seeded. The species is an allotetraploid derived from hybridization between
= 8) and
= 10). Its center of origin is uncertain but is most likely the Middle East, with possibly independent multiple origins within overlapping ranges of the putative parental taxa (S. I. Warwick and A. Francis 1994). Specimens from Delaware, District of Columbia, and Mississippi have not been observed, but are still listed here.