摘要
We describe a new species of Stegnogramma (Thelypteridaceae; Polypodiales) as Stegnogramma australis. Morphologically, it is most similar to S. griffithii, sharing the character of pinnate fronds with ternate terminal pinnae. However, S. australis can be distinguished from S. griffithii by having more free pinna pairs, shorter distal stipe hairs, and fewer included veinlets in the laminar areoles. A description, photographs of key characters, and the known distribution of the new species are presented. We also infer genome size and reproductive mode of the new species using flow cytometry. In addition, the occurrence of S. aspidioides in Vietnam is confirmed and a key to all known species of Stegnogramma in Vietnam is given.