Houstonia palmeri, the Saltillo bluet, is a plant species in the family Rubiaceae, native to the Mexican states of Coahuila and Nuevo León.Gray, Asa. 1882. Proceedings of the American Academy of Arts and Sciences 17: 202–203.
Two varieties are recognized:Kew World Checklist of Selected Plant Families
Houstonia palmeri var. palmeri Houstonia palmeri var. muzquizana (B.L.Turner) TerrellTerrell, Edward Everett. 2001. Taxonomic review of Houstonia acerosa and H. palmeri with notes on Hedyotis and Oldenlandia (Rubiaceae). Sida 19:913-922.
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