This name is a synonym of Sphaerostigma spirale var. clypeatum (H. Lév.) A. Nelson.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50107683) with original publication details: Monogr. Onothera 222 1905.
This name was in version 1 of The Plant List, record tro-50107683.