Dasylirion wheeleri S. Watson Dasylirion wheeleri S. Watson, Proc. Amer. Acad. Arts 14. 249. 1879 sec. Thiede 2012=Dasylirion wheeleri var. wislizenii (Trel.) Trel. in Repert. Spec. Nov. Regni Veg. 11: 53. 1912 syn. sec. Thiede 2012