Hi Steve,
Maurillio is right, it might be a form of albilanata, but the flower position and shape doesn't seem quite right to me. M. albilanata also does have some central spines, so my thought were closer to the crucigera / huitzilopochtlii complex. There are an awful lot of intermediate forms in this grouping.
I'd like to see a bigger picture of the whole plant if it were possible. And I don;t suppose you know where it came from (in Mexico I mean, not Home Depot!!).
_________________
Chris43, moderator