Birkie,

A picture of that would be most welcome. There are some Opuntia which flower differently from most Opuntia (after all, they stretch from northern British Columbia to Patagonia), but I don't remember the species.

Picture please.

I am throwing in a wild guess of Opuntia cochinellifera. It can put on some size so watch out. I have seen one 12' tall before our nast nasty cold front did it in. The pads a re a bit elongated and the flowers are red and more closed in structure. I might have misspelled that name. Ithink it is cold hardy to about 20 or so. The big one was planted under a tree in town and it is dead now that we had low teens for three nights last year. There is a varigated version also

Here is a link that might be useful: O. ochinellifera