This name is a synonym of Plagiobothrys tenellus (C.A.Mey. ex Ledeb.) A.Gray.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Proc. Amer. Acad. Arts 10: 57 1874.
This name was in version 1 of The Plant List, record kew-2797946, and has not been changed.