This name is a synonym of Juncus rigidus Desf..
The record derives from IOPI
(data supplied on 2012-03-23)
which reports it as a synonym (record 453900) with original publication details: in Fl. Afr. Nord 4: 281 1957.
This name record (from IOPI) 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 Juncus maritimus in version 1 of The Plant List.