Simplicior means simpler, referring to being simpler than A. aristata, of which it was considered to have been a variety.
Rhizome: long creeping, 5--8 mm diam., densely scaly, knotty.
Frond: 80 cm high by 20 cm wide, evergreen, monomorphic, but the fertile fronds are taller, narrower, blade/stipe ratio: 3:2.
Stipe: light green to dark at the base, spaced 0.5--4 cm apart, old stipes persistent, scales lanceolate, tan, vascular bundles: "4 or more in an arc" but only three are seen in the photo below.
Blade: 2-pinnate, but sometimes said to be more divided because of the downward-pointing pinnule of the lowest pinna, deltate or pentagonal, papery, dark green, lustrous above, pale below, below: hairlike scales.
Pinnae: 12 to 20 pair, after 3 or 4 pair, the remaining pinnae are very much reduced to a 1-pinnate series; pinnules large closest to the rachis (compared to the remainder) the downward-pointing one very large; costae grooved above, continuous from rachis to costae to costules; segments undivided to pinnatifid, somewhat imbricate (overlapping); margins shallowly dentate, finely spiny; veins free, forked, prominent on the lower surface.
Sori: round, between midrib and margin, indusium: reniform, attached at a sinus, sporangia: translucent.
Dimensionality: the blade is more or less held horizontally above a stipe that varies from vertical to 45°.
Habitat: rather dry mountain forests, often at foot of cliffs.
Distribution: Japan and China.
Hardy to -15°C, USDA Zone 7.
In North America the only form in commerce is the selection 'Variegata' with a light yellow-green band near the costae, or on smaller fronds, near the rachis.
Aspidium aristatum (G. Forster) Swartz var. simplicius Makino
Byrsopteris simplicior (Makino) Kurata
Polystichopsis simplicior (Makino) Tagawa
Rumohra simplicior (Makino) Ching