This name is a synonym of Acer negundo subsp. californicum (Torr. & A.Gray) Wesm..
The record derives from WCSP (in review)
(data supplied on 2012-03-26)
which reports it as a synonym with original publication details: Revis. Gen. Pl. 1: 146 1891.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:1838-2.
This name was in version 1 of The Plant List, record kew-2616046, and has not been changed.