Subspecies, varieties, forms and cultivars of plants belonging to the Frailea pumila group

• Frailea camaquensis L.Horst: becomes more cylindrical with time. Distribution: West of Minas de Camaqua, Rio Grande do Sul, Brazil
• Frailea carminifilamentosa Kilian ex Backeb.: has carmine filaments.
• Frailea pumila Britton & Rose: (subsp. pumila) has stems 2-3 cm in diameter and 13-15 ribs. Distribution: Argentina, Uruguay, and Paraguay.
• Frailea pumila subs. deminuta (Buining & Bredero) Prestlé: has stems about 2-3 cm in diameter, but only 17-20 ribs. Distribution: Livarmento, Rio Grande do Sul,
  Brazil.
• Frailea pumila var. maior F.Ritter
• Frailea pumila f. rubrispina hort.: has reddidsh spines. Origin: Cultivated form.
• Frailea pumila subs. uruguayana Prestlé