This name is a synonym of Isoetes virginica N. Pfeiff..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26602055) with original publication details: Phytologia 12: 392 1965.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:130589-2.
This name was in version 1 of The Plant List, record tro-26602055, and has not been changed.