Porlieria angustifolia (Engelm.) A. Gray Porlieria angustifolia (Engelm.) A. Gray in Smithsonian Contr. Knowl. 1: 28. 1852 sec. Villaseñor & al. 2013≡Guaiacum angustifolium Engelm., Memoir Tour N. Mexico [Wislizenus]: 113. 1848 syn. sec. FNA Ed. Committee 2016