Rhizomes slender, creeping, forming small colonies. Leaves 8-20cm long, bipinnate, the sterile pinnules ovate and lobed, the fertile lanceolate, thin-textured and bright green. Eastern Europe, northern and central Asia and North America, on limestone, in shaded sites. The atypical species of the genus with its creeping rootstock and a limey, fully shaded habitat. Seldom cultivated but worth trying.