Coryphantha difficilis (Quehl) Orcutt in Cactography: 3. 1926
Coryphantha difficilis in Cactography: 3. 1926
is new combination for Mammillaria difficilis in Monatsschr. Kakteenk. 18: 107. 1911
Coryphantha difficilis in Cactography: 3. 1926
Coryphantha difficilis in Cactography: 3. 1926
Taxon for this name