Names and synonyms
Thelocactus conothelos
ssp. conothelos (Regel & Klein) Backeb. & F. Knuth, Kaktus-ABC, 385 (1935).
Echinocactus conothelos Reg. & Klein, Ind. Sem. Hort. Petrop. 48 (1860). Gymnocactus conothelos Backeb., Die Cactaceae V: 2859 (1961). Torreycactus conothele (Regel & Klein) Doweld, Sukkulenty 1: 19 (1998). Thelocactus conothele var. albiflorus Kladiwa & Fittkau nom. nud., in Krainz, Die Kakteen, C VIII b, 1 IV (1975). Echinocactus smithii Muehlenpf. (nomen utique rejiciendum, Vienna Code Appendix V), Allg. Gartenzeitung 14: 370 (1846). Echinocactus saussieri Weber, Dict. Hort. Bois, 468 (1896). Thelocactus saussieri Berger, Kakteen, 257 (1929). Gymnocactus saussieri Backeb., Cact. Succ. J. (US) 23: 151 (1951).

ssp. argenteus (Glass & Foster) Glass, Ident. Guide Threatened Cacti of Mexico 1: TH/CON (1997).
Thelocactus conothelos var. argenteus Glass & Foster, Cact. Succ. J. (US) 44: 48 (1972). Torreycactus conothele var. argenteus (Glass & Foster) Doweld, Sukkulenty 1: 19 (1998). Torreycactus conothelos ssp. argenteus (Glass & Foster) Doweld, Sukkulenty 3: 37 (2000).

ssp. aurantiacus (Glass & Foster) Glass, Ident. Guide Threatened Cacti of Mexico 1: TH/CON (1997).
Thelocactus conothelos var. aurantiacus Glass & Foster, Cact. Succ. J. (US) 44: 48 (1972). Torreycactus conothele var. aurantiacus (Glass & Foster) Doweld, Sukkulenty 1: 19 (1998). Torreycactus conothelos ssp. aurantiacus (Glass & Foster) Doweld, Sukkulenty 3: 36 (2000).

ssp. flavus (Mosco & Zanovello) Mosco & Zanovello, Bradleya 18: 63 (2000).
Thelocactus flavus Mosco & Zanovello, Cactus & Co., 3: 20 (1999). Thelocactus panarottoanus Halda, Acta Mus. Richnov. Sect. natur. 5: 161 (1998).

ssp. garciae (Glass) Mosco & Zanovello, Bradleya 18: 63 (2000).
Thelocactus garciae Glass & M. Mendoza, Ident. Guide Threatened Cacti of Mexico 1: TH/GA (1997). Torreycactus conothelos ssp. garciae (Glass & Foster) Doweld, Sukkulenty 3: 36 (2000).