Description from Flora of China
Cardamine macrophylla var. crenata Trautvetter; C.
macrophylla var. dentariifolia J. D. Hooker & T. Anderson; C.
macrophylla var. diplodonta T. Y. Cheo; C. macrophylla var.
foliosa J. D. Hooker & T. Anderson; C. macrophylla var. lobata
J. D. Hooker & T. Anderson; C. macrophylla var. moupinensis
Franchet; C. macrophylla subsp. polyphylla (D. Don)
O. E. Schulz; C. macrophylla var. polyphylla (D. Don) T. Y. Cheo & R. C. Fang; C. macrophylla var. sikkimensis J. D. Hooker & T. Anderson; C. polyphylla D. Don (1825), not O. E. Schulz (1903); C. sachalinensis Miyabe & Miyake; C. sinomanshurica (Kitagawa) Kitagawa; C. urbaniana O. E. Schulz; Dentaria gmelinii Tausch; D. macrophylla (Willdenow) Bunge ex Maximowicz; D. sinomanshurica Kitagawa; D. wallichii G. Don; D. willdenowii Tausch.
Herbs perennial, (20-)30-95(-115) cm tall. Rhizomes creeping, not scaly, slender or stout and with tuberous knots, 2-10(-30) mm in diam., not stoloniferous. Stems stout or slender, erect, simple or rarely branched above, glabrous, hirsute, or pilose. Rhizomal leaves (4-)10-40(-50) cm; petiole (1-)3-20(-25) cm; terminal leaflet lanceolate, elliptic, oblong, ovate, or obovate, (1-)2-15(-25) × (0.5-)1-3.5(-5) cm, sessile or petiolulate, base cuneate, margin serrate, crenate, dentate, or rarely 3-5-lobed, apex acuminate, acute, or subobtuse; lateral leaflets (1 or)2-6 pairs, similar to terminal but smaller. Cauline leaves 3-12(-18); petiole (1-)2-5(-6.5) cm, not auriculate at base; terminal leaflet narrowly ovate, lanceolate, elliptic, or oblong, rarely obovate or lanceolate-linear, (2-)4-12(-20) × 1-4(-5) cm, glabrous or pubescent, sessile or on a petiolule to 1 cm, base cuneate, margin ciliolate and crenate, serrate, or serrulate, rarely subentire or doubly serrate, apex acute, rarely acuminate; lateral leaflets 2-7(-11) pairs, sessile or petiolulate, base cuneate or obliquely decurrent, similar to but slightly smaller than terminal leaflet. Racemes 10-30-flowered. Fruiting pedicels ascending or rarely divaricate, (0.3-)0.8-2.5(-3.1) cm, straight, stout. Sepals oblong, 3.5-6.5(-8) × 1.5-3 mm. Petals purple or lilac, obovate or spatulate, (0.8-)1-1.7 cm × 3.5-8 mm, apex rounded or rarely subemarginate. Median filament pairs 7-9(-11) mm, lateral pair 6-7 mm; anthers oblong, 1-2(-2.5) mm. Ovules 8-12(-16) per ovary. Fruit linear, (2.2-)2.5-6(-7) cm × 1.5-2.5(-3) mm; gynophore 0.5-3 mm; valves smooth, sparsely pubescent or glabrous; style (1-)2-6.5(-9) mm. Seeds brown, ovoid or oblong, (1.5-)2-3(-4) × 1-1.7(-2) mm. Fl. (Mar-) Apr-Oct, fr. May-Oct. 2n = 64, 80, 96.
The above first records from Anhui, Henan, Hunan, and Jiangxi are based on Yao 8927 (A), Boufford et al. 26199 (A, MO), Handel-Mazzetti (E, W, WU), and Tan Ceming 9604090 (MO), respectively.
Cardamine macrophylla is highly variable, especially in leaflet number, shape, size, base, and margin. An examination of several hundred specimens from the entire range of the species reveals that only a small number of the variants has been recognized formally in China, that the variation does not show any correlation among characters and/or geography, that some of the variants (on which varieties are based) occur within the same population, and that a thorough study at the population level is needed before the species is divided into infraspecific taxa. For example, leaflet number, in which var. polyphylla is said to have four or more pairs, is quite variable, though a maximum of seven pairs (e.g., Yü 22173, at A) was found in China, whereas serrate, serrulate, and doubly serrate leaflets were observed in one population (Al-Shehbaz et al. 9312, B, BM, E, G, K, MO). Serrate and doubly serrate leaflets also occur sporadically in C. leucantha and C. tangutorum.
Syntypes of Cardamine urbaniana represent robust plants with thick rhizomes and very large leaves. Schulz (Bot. Jahrb. Syst. 32: 280-623. 1903) separated the species from C. macrophylla primarily on the basis of its having thick rhizomes and sessile terminal leaflets. However, these two characters, as well as the cuneate vs. decurrent base of the lateral leaflets, do not correlate, and one finds various combinations of them in populations from Bhutan, China, Nepal, and Sikkim. Cardamine urbaniana is here lectotypfied on Henry 5635 (lectotype, GH; isolectotypes, G, K, US). The isolectotype at K has leaflets ca. 20 × 5 cm, which is the largest examined in the Brassicaceae.
Cardamine macrophylla is used medicinally, and the young parts are eaten as a vegetable.
Damp forests, river banks, tundra, rock crevices, meadows, damp woodlands, thickets, streamsides, valleys, ravines, mountain slopes, among boulders; 500-4200 m. Anhui, Gansu, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangxi, Jilin, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan, Zhejiang [Bhutan, India, Japan, Kashmir, Kazakhstan, Mongolia, Nepal, Pakistan, Russia, Sikkim].