Hymenophyllum polyanthos is a subcosmopolitan species of filmy-ferns. The group has been described as a complex of species and recent studies have pointed to genetic, morphological and ecological differences that can be used for a taxonomic revision of the group (Vasques et al. 2019). The specimen shown here was collected in Wakayama prefecture, and represents the fujisanense lineage, yet to be described as a new species in Japan.
Reference:
Vasques, D. T., Ebihara, A., Hirai, R. Y., Prado, J., & Motomi, I. (2019). Phylogeny of Hymenophyllum subg. Mecodium (Hymenophyllaceae), with special focus on the diversity of the Hymenophyllum polyanthos species complex. Plant Systematics and Evolution, 305(9), 811-825.