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 315567) with original publication details: Vidensk. Meddel. Naturhist. Foren. Kjøbenhavn 2: 39 1850.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:324798-2.
This name was in version 1 of The Plant List, record kew-315567.