Mammillaria heyderi subsp. macdougalii (Rose) D.R.Hunt, Mammillaria Postscripts 6: 10. 1997
Mammillaria heyderi subsp. macdougalii, Mammillaria Postscripts 6: 10. 1997
is new combination for Mammillaria macdougalii, Stand. Cycl. Hort. 4: 1982. 1916
Mammillaria heyderi subsp. macdougalii, Mammillaria Postscripts 6: 10. 1997