Knoxia purpurea (L.) Lam. ex Poir. Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Plantae phylum Tracheophyta class Magnoliopsida order Gentianales family Rubiaceae genus Houstonia species Houstonia purpurea Name Homonyms Knoxia purpurea (L.) Lam. ex Poir. Knoxia purpurea (L.) Lam.