This name is a synonym of Pycnanthemum montanum Michx..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 129348) with original publication details: Labiat. Gen. Spec. 331 1834.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:452128-1.
This name was in version 1 of The Plant List, record kew-129348, and has not been changed.