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 50088031) with original publication details: Contr. Gray Herb. 65: 40 1922.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:157451-2.
This name was in version 1 of The Plant List, record tro-50088031.