This name is a synonym of Allium sanbornii var. congdonii Jeps..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 295763) with original publication details: Fl. Calif. 1: 273 1921.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:8794-2.
This name was in version 1 of The Plant List, record kew-295763, and has not been changed.