Abstract
A new fern of Polystichum (Dryopteridaceae), P. asia-minoris, is described and illustrated from Horma Canyon in the borders of Küre Mountains National Park in Kastamonu Province located in the north of Turkey. Polystichum asia-minoris is distinguishable from the morphologically similar P. obliquum by having pinnae abaxially densely covered with broad-type microscales. It is not certain to which lineage the new species closely allied. The new species has extremely narrow distribution and is classified as Critically Endangered (CR) following IUCN Red List Criteria.