This name is a synonym of Trillium grandiflorum (Michx.) Salisb..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 454275) with original publication details: Contr. Lab. Bot. Univ. Montréal 14: 31 1929.
This name record (from WCSP) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Trillium grandiflorum in version 1 of The Plant List.