As classified in WFO snapshot
June 2024
Warning: older classification
variety
Echinocactus williamsii var. luteus
Rouhier
This variety name was first published in in Trav. Lab. Matiere Méd. Ecole Super. Pharm. Paris 17: 62. 1927.
This variety name has been reclassified since this snapshot. Its current preferred usage is a synonym .