Pilocereus monacanthus Lawr. in Gard. Mag. (London) 17: 319. 1841 Pilocereus monacanthus Lawr. in Gard. Mag. (London) 17: 319. 1841Taxon for this namePilocereus monacanthus Lawr. in Gard. Mag. (London) 17: 319. 1841