There is some work in progress regarding not following POWO for Cactaceae on iNaturalist. As for myself, I myself will not follow it for Opuntia, because it simply doesn't reflect reality, and is nothing more than a compilation of names. My main reason for flagging this particular species is to bring a group of psuedo-hybrids to light so we can further discuss them. Species of Opuntia that have been labelled as if hybrids, but with no supporting evidence.

The field for "reason" is small here. So, I'm elaborating a bit here. By listing these as so-called "hybrids" we are giving an impression that this is true, that these really are proven "hybrids". Yet it seems that it should behoove us, where possible, to present accurate information and not to just blindly follow some list (which, by the way is not required for iNaturalist, just strongly encouraged). The same "hybrid" status has been applied (mostly without evidence) to many of the other Opuntia names as well, but only some of them have been listed as hybrids here. Not a single one of these so-called hybrids has been reproduced / matched by actually cross-breeding the supposed parent species under controlled conditions, and so they are all based on suppostion. Primarily they have been an attempt (conscious or otherwise) to explain away confusing variation within a complicated and diverse genus. A similar case can be rationalized for almost every species in the genus as potentially being a "hybrid", IF one bases the argument on merely and solely the appearance of the plants, yet nearly all behave in the field as good reproducing biological species should. This issue is probably something that could (and will) be part of or a side branch to the Cactaceae discussion group. Opuntia will be one of the main "problem genera" in the family, along with some of the other more popular "collectors" genera that have an unrealistic proliferation of names following close behind. I can think of only one case where scientific evidence has been presented to support the contention of a hybrid origin of an Opuntia species, this being O. curvispina; however, in that case the evidence is merely highly suggestive and not proof, and regardless it is not a "hybrid" but rather it is a species of presumed hybrid origin. There is a huge difference between these two seemingly similar concepts, and even in this case there is no basis for adding the "X" to the species name. Populations of O. curvispina behave as a good, distinct, easily recognizable, stable, biologically reproducing species that shows no leanings toward either supposed parent (actualy one parent is not actually restricted to one, but a group of related entities), but I'm getting off track, and will leave it at this.

The same comments can be made about Opuntia occidentalis, except that it has never had anything but anecdotal evidence given to support it's status as a hybrid. It forms stable populations over a huge area, and reproduces true to type. There is no concrete evidence to support it being a hybrid of anything else, and it maintains its distinction from all the other types growing with it. In fact a circumstantial case could be made for it being the ancestral parental type to some of the other sympatric species.

So, bottom line, I think as a part of the overall Cactaceae discussion, we need to re-consider all of these Opuntia hybrid designations.

i think we need to reconsider most of hybrids and most of synonyms