Xanthium spinosum f. praecocius Bitter ex Widder Dataset GBIF Backbone Taxonomy Rank FORM Classification kingdom Plantae phylum Tracheophyta class Magnoliopsida order Asterales family Asteraceae genus Xanthium species Xanthium spinosum Name Homonyms Xanthium spinosum f. praecocius Bitter ex Widder Xanthium spinosum f. praecocius Bitter