|any temperate woodland fern of the genus Polystichum having shield-shaped flaps covering the spore-producing bodies: family Aspleniaceae|
any member of the fern genus Dryopteris, in the family Dryopteridaceae. The genus has about 250 species with worldwide distribution. Shield ferns are medium-sized woodland plants with bright green, leathery leaves that are several times divided. They have numerous round spore clusters (sori) attached along the veins on the underside of the leaves and protected by a tissue covering (indusium) that is reniform (kidney-shaped).
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