Description from Flora of China
Cardamine truncatolobata W. T. Wang; Loxostemon axillus Y. C. Lan & T. Y. Cheo.
Herbs perennial, (8-)13-35 cm tall, glabrous throughout or sparsely pilose. Rhizomes slender, thickened at stem base, with 1 or few stolons. Stems erect, slender, simple or 1- or 2-branched, flexuous. Basal leaves 1-3, 3- or 5(or 7)-foliolate; petiole (1.3-)2-6(-8) cm; terminal leaflet broadly obovate, 3-12 × 5-13 mm, with a petiolule 1-5(-8) mm, base subtruncate or rounded, margin entire or apically subtruncate or obtusely 3-lobed, ultimately mucronate; lateral leaflets 1 or 2(or 3) pairs, subsessile or petiolulate, somewhat similar to terminal leaflet but smaller. Cauline leaves (1 or)2-5(-7), 3- or 5-foliolate; petiole (0.8-)1.2-3 cm, not auriculate at base; terminal leaflet of uppermost leaves filiform, linear, or rarely narrowly oblanceolate, 0.5-2 cm × (0.3-)1-2 mm, attenuate at base, margin entire, apex acute. Racemes lax, (2-)5-14(-16)-flowered, rachis often flexuous. Fruiting pedicels erect or ascending, (0.8-)1-2.5(-3) cm, straight, glabrous, proximal ones often much longer than distal. Sepals ovate or oblong, 2.5-3.5 × 1.3-1.8 mm, glabrous, lateral pair subsaccate. Petals white, obovate, (6.5-)7-9 × 3.5-5 mm, not clawed, apex rounded. Median filament pairs 4-5 mm, slender; lateral pair 3-3.5 mm; anthers oblong, 0.8-1.1 mm. Ovules 8-14 per ovary. Fruit linear, (1-)1.5-2.5(-2.8) cm × 1-1.2 mm; valves glabrous, smooth; style (1-)1.5-3(-4) mm. Seeds brown, oblong, 1.2-1.6 × 0.8-1.2 mm, wingless. Fl. May-Jul, fr. Jun-Aug.
The above first record of Cardamine simplex from Sichuan is based on McLaren AC-19 (E, LE, P) and the type collection of C. truncatolobata.
The type collection of Cardamine simplex, Handel-Mazzetti 4310 (holotype, WU; isotypes, E, GH, NAS, W), resembles that of C. truncatolobata, Lan Kaiyong, Li Liangqian & Fei Yong 341 (holotype, PE; isotypes, KUN, PE), in every morphological aspect except for having narrower leaflets on the uppermost leaves and slightly lax racemes.
* Meadows, damp turf, marshy areas, stream- or ditchsides; 2500-3800 m. Sichuan, Yunnan.