Thelypteris sect. Parathelypteris H. Itô in Nakai & Honda, Nov. Fl. Jap. 4: 127. 1939; Wagneriopteris A. Löve & D. Löve.

Plants small to medium-sized, terrestrial plants, rarely in marshes or meadows. Rhizomes long creeping or short and decumbent, ascending or erect, glabrous or with scales or rusty yellow hairs. Fronds remote, approximate, or clustered; stipes stramineous or castaneous, ± polished, bases sometimes nearly black and glabrous or with spreading, grayish white, multicellular acicular hairs, distally glabrous or pubescent; laminae ovate-oblong, oblong-lanceolate, or lanceolate, tapering or not tapering to bases, pinnate-pinnatifid, acuminate and pinnatifid at apices; lateral pinnae mostly narrowly lanceolate to linear-lanceolate, bases symmetrical, truncate or broadly cuneate, not adnate to rachises, sessile or occasionally shortly stalked, apices acuminate; proximal pinnae not shortened or 1 to several pairs of pinnae obviously shortened, even reduced to small auricles, pinnatifid; segments mostly oblong, rectangular, or subsquare, margins entire or ± serrate, apices rounded-obtuse, sometimes pointed or with sinuslike angles. Veinlets pinnate, free, simple and all reaching margins. Laminae herbaceous or papery, when dry yellowish green, sometimes brownish green or nearly black, both surfaces ± with pubescent or acicular hairs, rarely glabrous when dry, sometimes with orange-yellow or reddish purple glands abaxially; costae grooved adaxially, densely covered with short setae, rounded and raised abaxially and usually ± with acicular hairs, rarely glabrous. Sori orbicular, medium-sized, dorsifixed at middle or near ends of veinlets, located between main veins and margins or slightly closer to margins; indusia larger, orbicular-reniform, sometimes horseshoe-shaped, when dry brown, membranous, glabrous or hairy, usually persistent. Spores bilateral, orbicular-reniform, perispores thin and transparent, corrugate, ± finely reticulate on surfaces. x = 8, 9, 31.

Parathelypteris is very similar to Metathelypteris in shape, but it differs by the costae grooved adaxially; the veinlets usually simple, not forked, and reaching margins; and the indusia larger and readily discerned.

The following taxa are excluded from the present treatment, pending further research: Parathelypteris auriculata H. G. Zhou & H. Li (Acta Bot. Yunnan. 14: 33. 1992), described from Guangxi (Wuming), and P. jinfoshanensis Ching & Z. Y Liu (Bull. Bot. Res., Harbin 4(3): 18. 1984), described from Sichuan (Nanchuan).

Coryphopteris Holttum (Blumea 19(1): 33. 1971) was restored recently. Fawcett et al. subdivided Parathelypteris sensu PPG1 into two genera Parathelypteris sensu stricto and Coryphopteris, classifying T. castanea, T. japonica, T. nipponica and related species into the latter genus.

About 60 species: tropical and subtropical regions of E Asia, SE Asia to Pacific islands; 24 species (11 endemic) in China.

(Authors: Lin Youxing (林尤兴); Kunio Iwatsuki)