This name is a synonym of Oxalis petrophila R. Knuth.
The record derives from Tropicos which reports it as a synonym (record 23700390) with original publication details: Repert. Spec. Nov. Regni Veg. 23: 279 279 1927.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:178183-2.