This name is a synonym of Galeopsis ladanum subsp. angustifolia (Ehrh. ex Hoffm.) Gaudin.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 85331) with original publication details: Deutschl. Fl. ed. 2, 1(2): 8 1795.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:447028-1.
This name was in version 1 of The Plant List, record kew-85331.