Drynaria lineatisora (Polypodiaceae), a long-overlooked new species from China, Myanmar and Vietnam based on morphological and molecular phylogenetic evidence

Drynaria lineatisora, a new fern species from China, Myanmar, and Vietnam, is described and illustrated here. This species is morphologically similar to D. coronans but can be clearly distinguished by its elongate-linear sori, dark brown scales with shortly spinulose-denticulate margins, and spiny spore ornamentation. In contrast, D. coronans has orbicular to short-linear sori, yellowish scales with long-ciliate margins, and smooth spore surfaces. Moreover, D. coronans is widely distributed across tropical and subtropical regions of Southeast Asia, whereas D. lineatisora shows a disjunct distribution limited to mountainous areas of Medog (Xizang, China), northern Myanmar, and northern Vietnam. Molecular phylogenetic evidence based on chloroplast genome further confirms significant divergence between the two species.