Ricotia cantoniensis Loureiro, Fl. Cochinch. 2: 482. 1793; Cardamine cryptantha (A. Richard) Kuntze var. pinnatodentata Kuntze; C. microsperma (de Candolle) Kuntze; Nasturtium microspermum de Candolle; N. microspermum var. vegetius Bunge; N. microspermum var. macilentum Bunge; N. sikokianum Franchet & Savatier; N. sikokianum var. axillare Hayata; Rorippa microsperma (de Candolle) Handel-Mazzetti.

Herbs annual, (5-)10-35(-45) cm tall, glabrous throughout, sometimes sparsely with semiglobose papillae 0.05-0.1 mm. Stems erect or decumbent, branched basally and above, rarely simple. Basal leaves petiolate, rosulate, soon withered, lyrate, pinnatisect, or bipinnatisect, up to 10 × 3 cm, with up to 12 lateral lobes on each side of midvein. Cauline leaves and bracts sessile or rarely petiolate throughout, auriculate or sagittate at base, lyrate, pinnatisect, or bipinnatisect, rarely sinuate or toothed, (0.8-)1.5-5(-7) × (0.3-)0.8-2.3(-3) cm; lateral lobes 2-6(or 7) on each side of midvein, to 10 × 5 mm, incised, dentate, or entire. Racemes bracteate throughout; bracts rarely adnate to pedicel. Fruiting pedicels stout, ascending, (0.3-)0.7-2(-3) mm. Sepals oblong or subelliptic, 1.5-2(-2.5) × 0.5-0.8 mm. Petals pale yellow, obovate or narrowly spatulate, 2-3(-3.5) × 0.5-1 mm. Filaments 1.5-2 mm; anthers oblong, 0.3-0.4 mm. Ovules 100-230 per ovary. Fruit broadly or narrowly oblong, (3-)4.5-8.5(-10) × 1.5-2.5 mm; valves thin papery, veinless; style 0.1-0.5 mm. Seeds reddish brown, ovate or ovate-reniform, foveolate, biseriate, (0.3-)0.4-0.6 × (0.2-)0.3-0.4 mm. Fl. and fr. Feb-Nov.

Fields, roadsides, valleys, river banks, along irrigation ditches, waste places, damp areas; near sea level to 1800 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Shaanxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Korea, Russia (Far East), Vietnam].