This name is a synonym of Juncus balticus subsp. mexicanus (Willd. ex Schult. & Schult.f.) Snogerup.
The record derives from IOPI
(data supplied on 2012-03-23)
which reports it as a synonym (record 314496) with original publication details: Pflanzenr. IV, 36: 146 1906.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:132011-2.
This name was in version 1 of The Plant List, record kew-314496.