polystichum

from The Century Dictionary.

• noun A genus of dryopteroid polypodiaceous ferns well marked by their erect habit, dryish texture, and chaffy vascular parts, and by having the ultimate divisions of the frond mainly auriculate and spinulose. It is distinguished from Dryopteris by its centrally peltate indusia. There are about 75 species, mainly boreal in distribution, many of them well known. See holly-fern, Christmas fern (under Christmas), and Aspidium, 1.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun small to medium-sized terrestrial ferns especially holly ferns; in some classification systems placed in Polypodiaceae