Opuntia In Arkansas

Long as I can remember, there was a huge Prickly Pear Cactus plant in town, growing beside the small engine repair shop next to the post office. The electric meter on the building is about eye level to me so it's easy to see the tallest pads are around 6' tall. I saw this cactus every day.  It sported beautiful yellow flowers in Spring and I often wondered what the large purple fruits, ripening in Fall were like to eat. So it turned out there were a few more of this particular cactus growing around here.  Somebody brought it in, got it started and shared cuttings or seedlings.  This is not the usual Opuntia humifusa which is the only species of native Prickly Pear to Arkansas and can be seen in fields and along fence rows, never getting over a foot tall and producing small, red fruit that's usually dry or eaten by wildlife before you can get to it. I didn't know much of anything about any kind of cactus up to this point in 2017, only that I wante