This name is a synonym of Cuphea hyssopifolia Kunth.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 19200649) with original publication details: Contr. U.S. Natl. Herb. 23(4): 1018 1924.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:183996-2.
This name was in version 1 of The Plant List, record tro-19200649.