Article (magazine)  (May 1965)  Page(s) 99-113, vol. 52.  
 
Species of the subgenus Hesperhodos are endemic to two widely separated areas of North America: R. minutifolia to western Baja California Norte...
[recites detailed botanical description of the species]
R. minutifolia Engelm. f. minutifolia - petals pink
R. minutifolia Engelm. f. albiflora W.H.Lewis - petals white - The white petaled form is said...to be "not common" and to form large patches around Ensenada and southward.

Article (magazine)  (1938)  Page(s) 74.  
 
The primitive form R. minutifolia Engelm. is diploid with 2x = 14. It has been placed in the genus Hesperhodos by Cockerell, a classification which is sustained by Boulenger and Hurst. This simple species has a very local distribution in south-western North America and Mexico. It is certainly related to Rosa and also to Potentilla (Boulenger, 1936 b) and indicates long-existent polyphyletic lines of descent in the group.