This name is a synonym of Agave salmiana subsp. crassispina (Trel.) Gentry.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 293729) with original publication details: Stand. Cycl. Hort. 1: 234 1914.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:6445-2.
This name was in version 1 of The Plant List, record kew-293729, and has not been changed.