Description from Flora of China
Sisymbrium dubium Persoon, Syn. Pl. 2: 199. 1807; Cardamine sublyrata Miquel; Nasturtium dubium (Persoon) Kuntze; N. heterophyllum Blume; N. indicum (Linnaeus) de Candolle var. apetalum de Candolle; N. indicum var. javanum Blume; N. sublyratum (Miquel) Franchet & Savatier; Rorippa heterophylla (Blume) R. O. Williams; R. indica (Linnaeus) Hiern var. apetala (de Candolle) Hochreutiner; R. sublyrata (Miquel) H. Hara.
Herbs annual, (4-)15-33(-45) cm tall, glabrous or rarely sparsely pubescent. Stems often branched basally and apically. Basal leaves withered by flowering. Lower and middle cauline leaves auriculate or not; petiole to 4 cm, rarely absent; leaf blade lyrate-pinnatipartite or undivided, obovate, oblong, or lanceolate, (2-)3-11(-15) × (0.5-)1-3(-5) cm, margin entire or irregularly crenate or serrate, apex obtuse or subacute; terminal lobe oblong, elliptic, or oblong-lanceolate, to 14 × 4 cm; lateral lobes absent or 1-4 on each side of midvein. Uppermost leaves usually sessile, auriculate or not; leaf blade lanceolate or oblong, margin entire or serrulate, apex acute or acuminate. Racemes ebracteate. Fruiting pedicels slender, divaricate, straight, (2-)3-8(-10) mm. Sepals often pinkish, ascending, oblong-linear, (2-)2.5-3 × 0.5-0.7 mm, margin membranous. Petals mostly absent, rarely present and linear or narrowly oblanceolate, 1.5-2.5 × 0.2-0.7(-1) mm, often shorter than sepals. Filaments 1.5-2.8 mm; anthers oblong, 0.5-0.8 mm. Ovules 70-90 per ovary. Fruit linear, (1.5-)2.5-4 cm × 0.7-0.9(-1) mm, straight; valves thin papery, not veined; style 0.2-1(-1.5) mm, stout and about as wide as fruit, rarely slender and narrower. Seeds reddish brown, subquadrate or ovate-orbicular, 0.5-0.8 × 0.4-0.6 mm, foveolate, uniseriate. Fl. and fr. throughout the year. 2n = 32*, 48*.
Valleys, waste areas, slopes, roadsides, wet grounds, grassy places, field margins; near sea level to 3700 m. Anhui, Fujian, Gansu, Guangdong, Gaungxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Shaanxi, Shandong, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Bangladesh, India, Indonesia, Japan, Laos, Malaysia, Myanmar, Nepal, Philippines, Sikkim, Thailand, Vietnam; naturalized in North and South America].