This name is a synonym of Riccia atromarginata f. glabra (Levier ex K. Müller) R.M. Schust..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 35204866) with original publication details: Lebermoose 6(1): 203 1907.
This name was in version 1 of The Plant List, record tro-35204866.