This name is a synonym of Apocynum androsaemifolium var. incanum A.DC..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 12942) with original publication details: Pittonia 5: 66 1902.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:16654-2.
This name was in version 1 of The Plant List, record kew-12942.