Echinocactus intricatus Link & Otto species synonym

Echinocactus horizontalis C.F.Först. species synonym

Echinocactus horizonthalonius var. laticostatus Schmoll variety synonym

Echinocactus horizonthalonius subsp. australis M.A.Baker subspecies accepted

Echinocactus pachycornis Muehlenpf. species synonym

Meyerocactus horizonthalonius subsp. nicholii (L.D.Benson) Doweld subspecies synonym

Echinocactus laticostatus Engelm. & J.M.Bigelow species synonym

Echinocactus horizonthalonius var. subikii Staník & Dráb variety synonym

Echinocactus horizonthalonius var. obscurispinus Rud.Mey. variety synonym

Echinocactus horizonthalonius subsp. nicholii (L.D.Benson) U.Guzmán subspecies accepted

Echinocactus horizonthalonius subsp. jarmilae Halda & Horáček subspecies synonym

Echinocactus horizonthalonius var. curvispinus Salm-Dyck variety synonym

Echinocactus horizonthalonius var. centrispinus Engelm. variety synonym

Echinocactus equitans Scheidw. species synonym

Notocactus intricatus (Link & Otto) Herter species synonym

Meyerocactus horizonthalonius (Lem.) Doweld species synonym

Echinocactus horizonthalonius subsp. horizonthalonius subspecies accepted

Melocactus intricatus Link & Otto species synonym

Echinocactus horizonthalonius var. equitans Schmoll variety synonym

Echinocactus horizonthalonius f. obscurispinus (Rud.Mey.) Schelle form synonym

Echinocactus horizonthalonius var. nicholii L.D.Benson variety synonym

Echinocactus horizonthalonius f. curvispinus (Salm-Dyck) Schelle form synonym

Echinocactus horizonthalonius f. centrispinus (Engelm.) Schelle form synonym