I have Datura wrightii, a beautiful Sonoran Desert perennial angel's trumpet. My strain is a cultivated strain. The flowers have all the parts. The anthers of open flowers seem to have no pollen at all, even when I cut them apart. Every flower produces a large fruit full of viable seeds. I have queried Sonoran Desert botanists; they tell me this species is known for self-pollination, which usually occurs before the flowers open.
I have been too lazy to ever go out and cut open a nearly-ready-to-open-bud, but maybe one of these days I'll get
a round tuit.