Cyste Dulac; Cystea J. Smith; Filix Adanson (1763), not Séguier (1754), nor Ludwig (1757); Rhizomatopteris A. P. Khokhrjakov.

Plants small, summer-green. Rhizomes long or shortly creeping, blackish brown, glabrate or densely red-brown pubescent, sparsely scaly; scales brown or brownish, thin, ovate to broadly lanceolate. Fronds distant, approximate, or caespitose, thin; stipe dark brown at base, upper part stramineous or chestnut-colored; lamina 2- or 3-pinnate, rarely 4-pinnate or more divided, ovate-lanceolate, ovate-triangular, or subpentagonal; pinnae with anadromous pinnules, shortly stalked, unequally sided or subequilateral at base; minutely toothed at segment margin; veins free, forked or pinnate, terminating in teeth or emarginations. Lamina thinly herbaceous or herbaceous, green when dried, stipe, rachis, costae, and costules with few small scales at base, and multicellular hairs or unicellular glandular hairs, lamina usually glabrate. Sori orbicular, abaxial on veins, sorophore slightly protuberant, annulus of sporangium consisting of 14-16 cells; indusia ovate, lanceolate, orbicular, or shallowly cup-shaped, attached at proximal side of sorophore, membranous, persistent, covering sporangia when young, hidden at maturity. Spores bilateral, dark brown, bean-shaped, perispore usually with spines, rarely with folds. x = 42.

The following taxon is excluded from the present treatment, pending further research: Cystopteris maborasensis Masamune (Trans. Nat. Hist. Soc. Formosa 28: 141. 1938), described from Taiwan.

More than 20 species and many hybrids: mainly in the temperate and frigid-temperate zones and in tropical mountains; 11 species (six endemic) in China.

(Authors: Wang Zhongren (王中仁); Christopher Haufler)