Coryphantha (Engelm.) Lem.
Bot. syn.: Glandulifera (Salm-Dyck) Fric.

Coryphantha arizonica:

Coryphantha arizonica (Engelm.) Britt. & Rose, Cactaceae: See Escobaria vivipara (Nutt.) Buxb. var. arizonica (Engelm.) D. R. Hunt.

Coryphantha elephantidens

Coryphantha elephantidens (Lem.) Lem.
Bot. syn.: Coryphantha garessii L.Bremer, Coryphantha sulcolanata (Lem.) Lem.

Coryphantha retusa

Coryphantha retusa (Pfeiff.) Britt. & Rose.
Bot. syn.: Cactus retusus (Pfeiff.) Kuntze, Mammillaria retusa Pfeiff.

I have no articles for this botanical term, but there might be some for the next level down (if found).