Meyerocactus horizonthalonius subsp. nicholii (L.D.Benson) Doweld in Sukkulenty 1(2): 27. 1999
Meyerocactus horizonthalonius subsp. nicholii in Sukkulenty 1(2): 27. 1999
is new combination for Echinocactus horizonthalonius var. nicholii, Cacti Ariz., ed. 3: 23. 1969