This name is a synonym of Cynanchum gerrardii (Harv.) Liede.
The record derives from Tropicos which reports it as a synonym (record 2602207) with original publication details: Thes. Cap. 2: 58, t. 191 58 1863.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:100920-1.