Physaria argentea (Pursh) MacMill. Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Plantae phylum Tracheophyta class Magnoliopsida order Brassicales family Brassicaceae genus Physaria species Physaria ludoviciana Name Homonyms Physaria argentea (Schauer) O'Kane & Al-Shehbaz Physaria argentea (Pursh) MacMill.