This name is a synonym of Diphasiastrum fawcettii (F.E. Lloyd & Underw.) Holub.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26619414) with original publication details: Bull. Torrey Bot. Club 27: 167 1900.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:147343-2.
This name was in version 1 of The Plant List, record tro-26619414, and has not been changed.