Etymology Rigens means rigid.

Description Rhizome: erect, short, thick, scales ovate-lanceolate, to 1.5 cm long, bright brown to pale brown.
Frond: 45 cm high by 20 cm wide, evergreen, monomorphic, blade/stipe ratio: 3:2.
Stipe: straw-colored above, darker at base, grooved, scales at base of stipes brown or blackish, continuing onto rachis, vascular bundles: 4 or more, in an arc.
Blade: 2-pinnate, lanceolate, glossy, leathery, linear to lanceolate scales below.
Pinnae: 11 to 18 pair, lanceolate, terminated with a long spine; pinnules the upper one closest to the rachis larger; margins serrate; veins free, forked.
Sori: round, in rows on both sides of the midrib, near to it, indusium: peltate, central.

Culture Habitat: open montane forests. Distribution: Japan, China. Hardy to -25°C, USDA Zone 5.