This name is a synonym of Atriplex prostrata subsp. calotheca (Rafn) M.A.Gust..
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Novit. Fl. Suec. Mant. 3: 164 1842.
This name was in version 1 of The Plant List, record kew-2665110.