| Ferocactus a - e | Ferocactus acanthodes ssp. acanthodes, acanthodes ssp. lecontei, diguetii, echidne, emoryi ssp. emoryi, emoryi ssp. rectispinus |
| Ferocactus f - o | Ferocactus flavovirens, fordii ssp. borealis, glaucescens, gracilis spp. gracilis, gracilis ssp. coloratus, gracilis ssp. gatesii, hamatacanthus ssp. hamatacanthus, hamatacanthus ssp. sinuatus, histrix, johnstonianus |
| Ferocactus p - z | Ferocactus peninsulae ssp. peninsulae, peninsulae ssp. santa-maria, pilosus, pottsii, robustus, schwarzii, viridescens ssp. viridescens, wislizeni ssp. wislizeni, wislizeni ssp. herrerae |