This name is a synonym of Isoetes occidentalis L.F. Hend..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26603623) with original publication details: Proc. U.S. Natl. Mus. 23(1226): 649 1901.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:130587-2.
This name was in version 1 of The Plant List, record tro-26603623, and has not been changed.