This name is a synonym of Allium howellii var. sanbenitense (Traub) Ownbey & Aase.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym and as an illegitimate name (record 296414) with original publication details: Leafl. W. Bot. 2: 110 1938.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:8865-2.
This name was in version 1 of The Plant List, record kew-296414, and has not been changed.