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

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

Melocactus intricatus Link & Otto species synonym

Meyerocactus horizonthalonius (Lem.) Doweld species synonym

Echinocactus horizonthalonius subsp. horizonthalonius subspecies accepted

Echinocactus horizonthalonius var. equitans Schmoll variety synonym

Echinocactus intricatus Link & Otto species synonym

Echinocactus horizontalis C.F.Först. species synonym

Echinocactus horizonthalonius var. laticostatus Schmoll variety synonym