O. debreczyi growing sympatrically with O. polyacantha scwheriniana. These are the only two Opuntia taxa in this area, and easily distinguishable. Related O. fragilis occurs not far away, but is not here.
In the second photo, O. debreczyi is to the left, and O. polyacantha schweriniana is to the right. They are similar in size; both are dwarf with cladodes only about 1.5 inches long on average (normally not over 2 inches).
The "x" does not belong on the species name here. O. debreczyi is a wide-ranging, common, and distinct species, not a local hybrid that pops up occasionally.