This name is a synonym of Antennaria monocephala subsp. angustata (Greene) Hultén.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record E6B8609D-4FC1-4CB8-A46D-C38E5985781B) with original publication details: Contr. Arnold Arbor. 6 1934.
This name was in version 1 of The Plant List, record gcc-118708.