Sinapis juncea Linnaeus, Sp. Pl. 2: 668. 1753; Brassica argyi H. Léveillé; B. cernua (Thunberg) F. B. Forbes & Hemsley; B. integrifolia (West) O. E. Schulz; B. japonica (Thunberg) Siebold ex Miquel; B. juncea subsp. integrifolia (West) Thellung; B. juncea var. crispifolia L. H. Bailey; B. juncea var. foliosa L. H. Bailey; B. juncea var. gracilis M. Tsen & S. H. Lee; B. juncea var. integrifolia (Stokes) Sinskaya; B. juncea var. japonica (Thunberg) L. H. Bailey; B. juncea var. longidens L. H. Bailey; B. juncea var. longipes M. Tsen & S. H. Lee; B. juncea var. multisecta L. H. Bailey; B. juncea var. multiceps M. Tsen & S. H. Lee; B. juncea var. rugosa (Roxburgh) Kitamura; B. juncea var. strumata M. Tsen & S. H. Lee; B. juncea var. subintegrifolia Sinskaya; B. lanceolata (de Candolle) Lange; B. napiformis (Paillieux & Bois) L. H. Bailey var. multisecta (L. H. Bailey) A. I. Baranov; B. rugosa (Roxburgh) L. H. Bailey; B. taquetii H. Léveillé; B. willdenowii Boissier; Raphanus junceus (Linnaeus) Crantz; Sinapis cernua Thunberg; S. chinensis Linnaeus var. integrifolia Stokes; S. cuneifolia Roxburgh; S. integrifolia West; S. japonica Thunberg; S. lanceolata de Candolle; S. patens Roxburgh; S. ramosa Roxburgh; S. rugosa Roxburgh.

Plants annual. Taproots slender, cylindric, rarely to 1.5 cm in diam. Basal leaves with a slender, nonfleshy petiole; midvein not flattened; leaf blade 4-30 cm, margin highly variable. Fl. Mar-Jun, fr. May-Jul. 2n = 36*.

Cultivated for seed oil and medicine and as a vegetable and condiment. It is a naturalized weed on all continents except Antarctica.

Fields, waste places, roadsides. Cultivated throughout China, sometimes naturalized [widely cultivated and naturalized elsewhere].