I can't speak to which species (or variety, as the case may be) it is.
I do grow M. nuttallii in my yard, though. It normally blooms in the late spring/early summer. But, if it's mowed off after blooming, and we get some rain, it will rebloom in late summer/fall.
Never tried growing it in a hanging basket, but I'd be a little surprised if it worked. There's a pretty amazing root system underneath that seemingly unassuming plant. It doesn't look like the sort of root that would do well if confined to a pot.
