Synonyms: Cereus poselgeri (homotypic); Cereus tuberosus (heterotypic); Echinocereus kroenleinii (homotypic); Echinocereus poselgeri gerhardii; Echinocereus poselgeri kroenleinii (homotypic); Echinocereus tamaulipensis; Echinocereus tamaulipensis deherdtii; Echinocereus tamaulipensis var. brevissima; Echinocereus tamaulipensis waldeisii (homotypic); Echinocereus tuberosus (homotypic); Echinocereus waldeisii; Wilcoxia kroenleinii; Wilcoxia poselgeri (homotypic); Wilcoxia tamaulipensis; Wilcoxia tamaulipensis var. brevispina; Wilcoxia tamaulipensis var. brevissima; Wilcoxia tuberosa (heterotypic)