This name is a synonym of Eryngium aquaticum var. floridanum (J.M.Coult. & Rose) Mathias & Constance.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Bot. Gaz. 13: 142 1888.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:96325-2.
This name was in version 1 of The Plant List, record kew-2799281, and has not been changed.