The genus Thelocactus 

Thelocactus rinconensis subsp. icamolensis J. J. Halda et P. Kupcak, Acta Mus. Richnov. Sect. natur. 7: 75 (2000).

Descriptio: affinis subsp. rinconensis, sed plantis minoribus, ad 200mm latis et 60mm latis; flores minoribus ad 30mm longis, perianthii phylla obovata, atropurpurea.
Taproot thin, ca 100mm long; stem single, much smaller than ssp. rinconensis (up to 200mm across and 60mm tall); flowers small, up to 30mm long, with dark purple obovate leaflets.
Holotypus: PR no. JJH8504545, leg. J. J. Halda 7. 4. 1985.
Patria et Distributio: Mexico septentrionalis: Nuevo Leon (in vicinitate pagi Icamole) in summo collis, solo calcareo ad 1600 m supra mare.