This name is a synonym of Nematanthus serpens (Vell.) Chautems.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50261166) with original publication details: Fl. Flumin. 257 1825.
This name was in version 1 of The Plant List, record tro-50261166, and has not been changed.