Dahlia tenuicaulis P.D. Sørensen Dahlia tenuicaulis P.D. Sørensen, Rhodora 71: 335. 1969 sec. Carrasco-Ortíz & al. 2019Holotype: Mexico, Oaxaca, about 13 mi NE of Ixtlán de Juárez along route 175 to Tuxtepec, T.E. Melchert & P.D. Sorensen 6194 (IA)