This name is a synonym of Micranthemum umbrosum (J.F.Gmel.) S.F.Blake.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 29202267) with original publication details: Sketch Bot. S. Carolina 1(1): 18 1816.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:805802-1.
This name was in version 1 of The Plant List, record tro-29202267.