Onychium japonicum
Onychium japonicum is a species of fern in the family Pteridaceae. Taxonomy. The species was first described in 1784 by Carl Peter Thunberg as "Trichomanes japonicum". In 1825, Blume used the name ""Onychium"" for a genus of orchids, but this was illegitimate since it had been used in 1820 for the fern genus. Blume also used the combination ""Onychium japonicum"" for an orchid (now "Dendrobium moniliforme"). In 1848, Kunze transferred "Trichomanes japonicum" to the fern genus "Onychium" as "Onychium japonicum". The name "Onychium japonicum" is conserved against "Onychium japonicum" .