This name is a synonym of Mentzelia laevicaulis (Douglas) Torr. & A. Gray.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50088035) with original publication details: Contr. U.S. Natl. Herb. 25: 363 1925.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:157379-2.
This name was in version 1 of The Plant List, record tro-50088035.