Blechnum stenopterum Hance, J. Bot. 21: 268. 1883; Lomaria stenoptera (Hance) Baker; Plagiogyria argutissima Christ; P. henryi Christ; P. petelotii Copeland.

Stipes (3-)4-8(-12) cm on sterile fronds, (9-)11-22(-28) cm on fertile fronds, distally tetragonal in cross section; vascular bundle V-shaped; stipes and rachises glabrous; aerophores cushionlike, present only on stipe base. Sterile lamina pinnatifid, 20-60 × 4-20 cm, not glaucous, apex confluent, terminating in a pinnatilobed segment; rachises abaxially flattened or carinate distally, sometimes with crisped wings; pinnae 25-35 pairs; proximal pinnae reduced to auricles, middle pinnae adnate to rachises, basiscopically straight or rounded in large fronds; distal pinnae subequilaterally adnate to rachises, basiscopically decurrent; veins mostly forked above base. Fertile lamina pinnate, (10-)35-55(-75) × 4-8(-12) cm; rachises abaxially flattened to grooved, sometimes winged; pinnae 15-30 pairs, subsessile or shortly stalked; some proximal pinnae becoming aerophore-like vestiges or replaced by auriculate pinnae. Paraphyses absent. Spores yellow, with reddish tubercles.

"Plagiogyria stenoptera var. major" (Ching, Acta Phytotax. Sin. 7: 152. 1958) belongs in synonymy here; however, it was not validly published because no type was indicated (Melbourne Code, Art. 40.1).

Densely forested mountains, wet ravines, rocky slopes; 500-2500 m. Guangxi, Guizhou, Hubei, Hunan, Sichuan, Taiwan, Yunnan [Japan (Yakushima), Philippines (Luzon), Vietnam].