These grow like weeds in my garden. Related to "Jimson Weeds", but perennial. Used to be called "Datura meteloides", but now it's "Datura wrightii". From moist places in the subtropical southwestern USA; I have seen them wild along the Sacramento River in Sacramento, California. I have their South American cousins Brugmansias too, but Daturas seem to perform a lot better in my climate. They die back to a caudex but come back promptly.
The flowers only come in white, or white edged with purple. These have a faint purple edge but invisible in the photograph as it is too faint. I would have liked more purple on the edge.
They have a strong lemony fragrance at night. Pollinated by bats and hawkmoths.
Scale of the things: those blossoms are about 10 inches wide and maybe 18 inches long.