This name is a synonym of Osmunda japonica f. divisa (Makino) Tagawa.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26612301) with original publication details: in Makino & Nemoto, Fl. Jap. 1566 1925.
This name was in version 1 of The Plant List, record tro-26612301, and has not been changed.