Polystichum craspedosorum (Maxim.) Diels

Shield fern

Etymology Craspedosorum is from kraspedon, fringe + sorum, the spore dots, seemingly referring to fringed sori.
Description Rhizome: erect, small, bearing a few fronds in a whorl, persistent into the next season, scales lanceolate, gradually narrowing towards caudate apex, 2--4 mm long, brown.
Frond: 18 cm high by 4 cm wide, evergreen, monomorphic, blade/stipe ratio: 6:1.
Stipe: grooved, rather densely scaly throughout, vascular bundles: 4 or more, in an arc.
Blade: 1-pinnate, lanceolate, blades almost horizontal, widest at the middle, the proliferous tip rooting, papyraceous. matt-green, lanceolate to linear, rachis with yellowish brown to brown, and hair-margined scales, pinnae with linear scales on lower surface.
Pinnae: 20 to 35 pair, oblong-ovate, round at apex, short-stalked, 1--3 cm long; margins shallowly dentate ; veins free, forked, anadromic.
Sori: round, in 1 rows near the margin, indusium: peltate, large, persistent, overlapping, brown, central.
Culture Habitat: on rocky slopes in moist places in mountain forests, often forming colonies. Distribution: eastern Siberia, China, Japan, Korea, Manchuria. Hardy to -25░C, USDA Zone 5.
Synonyms
Aspidium craspedosorum Maxim.
Ptilopteris craspedosora (Maxim.) Hayata
Dryopteris craspedosora O. Ktze.
Hemesteum craspedosorum LÚveillÚ
Polystichum leucochlamys Christ
Ptilopteris craspedosora (Maxim.) Hayata
Polystichum craspedosorum
Polystichum craspedosorum. Sori lead-gray.  Photo: Hideto Araki, from the site Ferns in Japan, with permission.
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