You selected Echinomastus johnsonii (Parry ex Engelm.) E.M. Baxter. This is a synonym for:

Accepted scientific name:
Sclerocactus johnsonii (Parry ex Engelm.) N.P. Taylor (accepted name) 1 literature reference for Sclerocactus johnsonii (Parry ex Engelm.) N.P. Taylor
Synonyms:
Echinocactus johnsonii Parry ex Engelm. (synonym) 2 literature references for Echinocactus johnsonii Parry ex Engelm.
Echinocactus johnsonii var. lutescens Parish (synonym) 2 literature references for Echinocactus johnsonii var. lutescens Parish
Echinomastus johnsonii (Parry ex Engelm.) E.M. Baxter (synonym) 2 literature references for Echinomastus johnsonii (Parry ex Engelm.) E.M. Baxter
Neolloydia johnsonii (Parry ex Engelm.) L. Benson (synonym) 3 literature references for Neolloydia johnsonii (Parry ex Engelm.) L. Benson
Neolloydia johnsonii var. lutescens (Parish) W.T. Marsh. ex R.G. Engard (synonym) 2 literature references for Neolloydia johnsonii var. lutescens (Parish) W.T. Marsh. ex R.G. Engard
Infraspecific taxon: Sclerocactus johnsonii (Parry ex Engelm.) N.P. Taylor
Common names: -
Classification:
Plantae
Phylum Magnoliophyta
Class Magnoliopsida
Order Caryophyllales
Family Cactaceae
Genus Sclerocactus
Distribution: North America
Additional data: -
Source database: ITIS, Sep 2009
Latest taxonomic scrutiny: Kartesz J., 15-Mar-2000
Online resource: http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=505078
CoL taxon LSID: urn:lsid:catalogueoflife.org:taxon:24d49262-60a7-102d-be47-00304854f810:ac2010