This name is a synonym of Washingtonia robusta H.Wendl..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 339833) with original publication details: Contr. W. Bot. 15: 48 1929.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:267792-2.
This name was in version 1 of The Plant List, record kew-339833, and has not been changed.