This name is a synonym of Nepeta laevigata (D.Don) Hand.-Mazz..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 454071) with original publication details: Repert. Spec. Nov. Regni Veg. 9: 245 1911.
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 Nepeta spicata in version 1 of The Plant List.