Echinocactus species. A E. platyacanthus from Querétaro B E. horizonthalonius from Chihuahua C H. texensis from Chihuahua D H. parryi from Chihuahua EH. polycephala subsp. polycephala from Sonora F K. grusonii from Querétaro. Line bar in fruit photographs is 1 mm.

  Part of: Vargas-Luna MD, Hernández-Ledesma P, Majure LC, Puente-Martínez R, Macías HMH, Luna RTB (2018) Splitting Echinocactus: morphological and molecular evidence support the recognition of Homalocephala as a distinct genus in the Cacteae. PhytoKeys 111: 31-59.