This name is a synonym of Hieracium scouleri Hook..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record AADFF7FF-1166-466B-9488-60FA5A4D2A0D).
This name record (from TICA) 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 Hieracium cynoglossoides in version 1 of The Plant List.