Houstonia purpurea var. montana Chick. Dataset GBIF Backbone Taxonomy Rank VARIETY Classification kingdom Plantae phylum Tracheophyta class Magnoliopsida order Gentianales family Rubiaceae genus Houstonia species Houstonia purpurea Name Homonyms Houstonia purpurea var. montana (Small) Terrell Houstonia purpurea var. montana Chick.