This name is a synonym of Plantago sericea subsp. sericans (Pilg.) Rahn.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 25200226) with original publication details: Bot. Jahrb. Syst. 62: 80 1928.
This name was in version 1 of The Plant List, record tro-25200226, and has not been changed.