This name is a synonym of Mentzelia nuda var. stricta (Osterh.) H.D. Harr..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50088027) with original publication details: Publ. Univ. Oklahoma Biol. Surv. 2: 73 1930.
This name was in version 1 of The Plant List, record tro-50088027.