This name is a synonym of Callitriche heterophylla Pursh.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 31533) with original publication details: Monogr. Callitriche 54 1864.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:429964-1.
This name was in version 1 of The Plant List, record kew-31533.