This name is a synonym of Cynanchum pachyphyllum (Decne.) K.Schum..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 2605064) with original publication details: Revis. Gen. Pl. 2: 425 1891.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:265622-2.
This name was in version 1 of The Plant List, record tro-2605064, and has not been changed.