This name is a synonym of Yucca glauca Nutt..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 452428) with original publication details: J. Linn. Soc., Bot. 18: 227 1880.
This name record (from WCSP) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Yucca angustifolia in version 1 of The Plant List.