Coryphantha werdermannii Boed. Coryphantha werdermannii Boed. in Monatsschr. Deutsch. Kakteen-Ges. 1: 155. 1929 sec. Hunt 2016=Coryphantha werdermannii subsp. unguispina Halda, Kupcák & Sladk. in Acta Mus. Richnov., Sect. Nat., 7: 34. 2000 syn. sec. Guzmán & al. 2003