This name is a synonym of Cynanchum blandum (Decne.) Sundell.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 2609700) with original publication details: Kew Bull. 1958: 98 1958.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:222609-2.
This name was in version 1 of The Plant List, record tro-2609700.