Melocactus curvispinus subsp. dawsonii (Bravo) N.P. Taylor Melocactus curvispinus subsp. dawsonii (Bravo) N.P. Taylor in Bradleya 9: 77. 1991 sec. Hunt 2016≡Melocactus dawsonii Bravo in Cact. Suc. Mex. 10: 28. 1965 syn. sec. Guzmán & al. 2003