This name is a synonym of Megalastrum pulverulentum (Poir.) A.R. Sm. & R.C. Moran.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26607759) with original publication details: Symb. Antill. 9: 305 1925.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:85216-2.
This name was in version 1 of The Plant List, record tro-26607759.