This name is a synonym of Saxifraga cespitosa subsp. laxiuscula (Engl. & Irmsch.) Á. Löve & D. Löve.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50324876) with original publication details: Pflanzenr. 67[IV,117(1)]: 371 1916.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:293588-2.
This name was in version 1 of The Plant List, record tro-50324876, and has not been changed.