This name is a synonym of Carex impura Ohwi.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 465334) with original publication details: J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 8: 250 1962.
This name record (from WCSP) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Carex aphyllopus in version 1 of The Plant List.