Cyrtomium calcis sp. nov. and six new records of the shield fern family (Dryopteridaceae) from Vietnam

Abstract

We describe a new species of Cyrtomium, C. calcis, from northern Vietnam and southern China, and report new records of six species in two fern genera, Arachniodes and Polystichum, of Dryopteridaceae, i.e., Arachniodes amabilis (from Lamdong Province), A. amoena (Quangtri Province), A. fengii (Nghean Province), A. globisora (Thanhhoa, Quangtri, and Laocai provinces), and A. nigrossora (Vinhphuc Province), and Polystichum ariticulatipilosum (Hagiang Province). The new species of Cyrtomium most closely resembles C. pachyphyllum, but can be distinguished from the latter in the shape of petiole scales, number of lateral pinna pairs, venation, and lamina shape. Detailed description, images, notes, type information, examined specimens, distribution, and habitat are provided for the new species and new records. The status of the new species is provisionally assessed here as endangered (EN) following the IUCN Categories and Criteria.