Thelocactus panarottoanus Halda, Acta Mus. Richnov. Sect. natur. 5: 161 (1998).


   Descriptio: Species in editione prima operis nostri depicta, T. rinconensi proxima, sed flores anguste infundibuliformes, auratae; semina T. conotheli similis.
   Corpus globosum, 70-150mm diametiens, (postem multicephalum ad 400mm diametiens), pars eius olivacea vel purpurascentia; tubercula conica, usque ca 25mm longa et 35mm lata. Spinae centrales plerumque 5, 100-120mm longae; spinae laterales 7-8, 20-40mm longae, albae, luteae vel tenebrae. Flores anguste infundibuliformes, autem latiores ad 35mm ostendit; perianthii phylla lanceolata, ca 30mm longa, integerrima, atroaurei-lutea, externa stria media purpurea ornata. Fructus urniformis, ca 15mm longus. Semen nigrum, ca 3×1.5mm magnum; testa microgranulata; hilum ca 1mm longum.

   Holotypus: PR no. PP8502130 leg. Paolo Panarotto 10.2.1985.
   Patria et Distribution: Mexico septentrionalis, San Luis Potosi [in vicinitate pagi La Hincada], in declivibus petrosis, solo calcareo ad 1100m supra mare.