This name is a synonym of Phoradendron leucarpum subsp. macrophyllum (Engelm.) J.R. Abbott & R.L. Thompson.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50241765) with original publication details: Syst. Bot. Monogr. 66: 419 2003.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:70030092-1.
This name was in version 1 of The Plant List, record tro-50241765.