Houstonia palmeri explained

Houstonia palmeri, the Saltillo bluet, is a plant species in the family Rubiaceae, native to the Mexican states of Coahuila and Nuevo León.^[1]

Two varieties are recognized:^[2]

• Houstonia palmeri var. palmeri
• Houstonia palmeri var. muzquizana (B.L.Turner) Terrell^[3]

Notes and References

1. https://www.biodiversitylibrary.org/page/8780828#page/218/mode/1up Gray, Asa. 1882. Proceedings of the American Academy of Arts and Sciences 17: 202–203.
2. http://apps.kew.org/wcsp/namedetail.do?name_id=100387 Kew World Checklist of Selected Plant Families
3. https://www.biodiversitylibrary.org/page/9308016#page/941/mode/1up Terrell, Edward Everett. 2001. Taxonomic review of Houstonia acerosa and H. palmeri with notes on Hedyotis and Oldenlandia (Rubiaceae). Sida 19:913-922.