This name is a synonym of Saxifraga oppositifolia f. albiflora (Lange) Fernald.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50088839) with original publication details: Consp. Fl. Groenland. 66 1880.
This name was in version 1 of The Plant List, record tro-50088839, and has not been changed.