This name is a synonym of Dioon edule var. angustifolium (Miq.) Miq,.
The record derives from WCSP
(data supplied on 2012-03-26)
which reports it as a synonym (record 383586) with original publication details: Kalmia 13: 5 1983.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:922058-1.
This name was in version 1 of The Plant List, record kew-2769003.