Coryphantha clava var. schlechtendalii (Poselg.) Heinrich ex Backeb., Cactaceae 5: 3040. 1961 Coryphantha clava var. schlechtendalii (Poselg.) Heinrich ex Backeb., Cactaceae 5: 3040. 1961Taxon for this nameCoryphantha clava var. schlechtendalii (Poselg.) Heinrich ex Backeb.