Houstonia coerulea var. elatior (Michx.) Pursh Dataset GBIF Backbone Taxonomy Rank VARIETY Classification kingdom Plantae phylum Tracheophyta class Magnoliopsida order Gentianales family Rubiaceae genus Houstonia species Houstonia caerulea Name Homonyms Houstonia coerulea var. elatior (Michx.) Pursh