Arabis holboellii subsp. retrofracta (Graham) Dataset GBIF Backbone Taxonomy Rank SUBSPECIES Classification kingdom Plantae phylum Tracheophyta class Magnoliopsida order Brassicales family Brassicaceae genus Boechera species Boechera retrofracta Name Homonyms Arabis holboellii var. retrofracta (Graham) Rydb. Arabis holboellii subsp. retrofracta (Graham) Arabis holboellii var. retrofracta (Graham) Jeps.