@brcacti We are not combining P.royenii with P.polygonus here but rather making all P.royenii = Pilosocereus. I implore you to read the articles cited to understand why this change is happening, it has little to do with morphological characters and more to do with taxonomic messes. The material of the Puerto Rican Bank is now names Pilosocereus armatus. P.royenii is now a synonym of P.polygonus as it preceded the naming of Puerto Rican Bank material with said name. Furthermore P.royenii sensu lato was strictly a PR Bank species before, and here you can see how they have named columnar cacti from all over the Neotropics with that name, a crass error.

I implore you to read the papers cited for the change to understand. iNat follows POWO KEW taxonomy and in there P.royenii is a synonym of P.polygonus.