Isopyrum dalzielii J. R. Drummond & Hutchinson, Bull. Misc. Inform. Kew 1920: 163. 1920; I. flaccidum Ulbrich; I. pteridifolium Handel-Mazzetti.

Plant glabrous. Rhizome ca. 3 cm. Leaves 3--11, basal, 11--15-foliolate, papery, glabrous; petiole 3.5--11.5 cm; leaf blade pentagonal, 3.5--10 cm wide; lateral leaflets petiolulate; leaflet blade obliquely rhombic to obliquely ovate, unequal in size, smallest ones ca. 8 × 4 mm; central leaflet rhombic, 2.5--6.5 (--7.5) × 1.7--3(--3.5) cm, base cuneate, margin distally lobulate or crenate and toothed, apex obtuse. Flowering stems 3--11, 20--28 cm tall, 3--8-flowered; bracts sessile, 3-sect, lower bracts 1--2.1 cm, upper bracts 2--3 mm. Flowers 1.4--1.8 cm in diam. Pedicel 2--3 cm. Sepals white, obovate-elliptic, 8--10 × 3.8--4 mm, apex slightly acute to obtuse. Petal limbs suborbicular, 2.8--4.5 mm, apex retuse or entire, apically mucronate; claw longer than limb. Stamens numerous, 3.5--4.5 mm; anthers broadly ellipsoid, ca. 0.8 mm. Follicles obovoid-lanceolate, 11--12 mm; persistent styles ca. 2 mm. Seeds brown, subglobose, ca. 1 mm, smooth. Fl. Apr--May, fr. May--Jun.

* Forests, shady and wet places by streams; 700--1600 m. Anhui, W Fujian, Guangdong, Guangxi, Guizhou, Hainan, SW Hubei, S Hunan, Jiangxi, SE Sichuan, Zhejiang.