Opuntia x rooneyi is a hybrid species, between
opuntia aureispina and
opuntia macrocentra, and like the former it is only found in the Big Bend area of west Texas. The oval-shaped, greenish blue pads have diagonal rows of areoles which bear 1 to 4 radial spines, about half an inch or less in length, and 2 or 3 thicker central spines, up to 2 inches long. Spines are concentrated at the areoles on the upper two thirds of the pads, and are light to dark reddish-brown in color. This hybrid was recognized relatively recently, around 2001.