Description from Flora of China
Cardamine multijuga Franchet var. gracilis O. E. Schulz, Repert. Spec. Nov. Regni Veg. 17: 289. 1921.
Herbs perennial, 10-35(-50) cm tall, glabrous throughout, semiaquatic. Rhizomes slender, to 10 cm or longer, 0.5-3 mm in diam. Stems erect, simple, striate angled, rooting from lower and sometimes middle nodes. Basal rosettes absent. Cauline leaves 10-20 per stem, (1.5-)2.5-7.5(-9) cm × (1.5-)4-14(-17) mm; petiole absent or rarely to 2 mm; terminal leaflet narrowly obovate, oblong, or rarely broadly ovate, (2-)3-8(-9) × (0.5-)1.5-5(-7) mm, petiolule 0.5-2 mm, base cuneate or rarely obtuse, margin obscurely 1-3-toothed on each side, apex acute, submucronate; lateral leaflets (6 or)7-12(-15) pairs, linear or narrowly oblong, asymmetric, slightly smaller than terminal lobe, sessile or rarely with a petiolule to 0.5 mm, base oblique, proximal margin 1- or 2(or 3)-toothed, distal margin entire or rarely obscurely 1- or 2-toothed, apex acute; proximal pair of lateral leaflets auriclelike, attached at or just above node, often giving appearance of amplexicaul leaf base. Racemes terminal, 10-20-flowered. Fruiting pedicels divaricate, 0.8-2.2 cm, slender. Sepals oblong or ovate, 3-4 × 1.2-2 mm, spreading, margin membranous, base of lateral pair subsaccate. Petals lavender with darker veins, spatulate, 6-8 × 2-3 mm, spreading, apex rounded. Filaments spreading, dilated at base, subequal, median pairs 3.5-5 mm, lateral pair 3-4.5 mm; anthers narrowly oblong, 1.3-1.6 mm. Ovules 10-14 per ovary. Fruit linear, 2-4 cm × ca. 1.5 mm; gynophore ca. 0.5 mm; valves smooth, glabrous; style 4-6 mm. Seeds brown, oblong, 1.7-2 × ca. 1.3 mm, winged all around; wing ca. 0.4 mm wide. Fl. Jun-Aug, fr. Jul-Oct.
This species, as Cardamine multijuga var. gracilis, was said to occur in Bhutan (Fl. Bhutan 1(2): 432. 1984), but the present authors have seen no material from that country. On the basis of having white flowers with smaller (4-6 mm) petals, it is likely that the record from Bhutan belongs to another species.
* Marshlands, lake shores, margins of ponds, ditches, open pastures; 2400-3300 m. Yunnan.