This name is a synonym of Southbya tophacea (Spruce) Spruce.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 35210450) with original publication details: Hepat. Pyren. 23 1847.
This name was in version 1 of The Plant List, record tro-35210450, and has not been changed.