Datura 'Wrightii' or 'Inoxia' which are two of our favorites beside the D. Missour Marble that has the variegated leaves. Happy Growing!!

Belle Blanche and Horn of Plenty are synonyms for Datura metel var. metel. These plants have single, white blooms, smooth stems, and bumpy seed pods which might be a little spiky. Here's a picture of the seed pod:
http://www.hear.org/pier/images/dametp2.jpg

Evening Fragrance refers to Datura inoxia, which is also a single white Datura, but it has pubescent (hairy) stems and very spiny seed pods. It is often remarked that the fragrance of D. inoxia resembles that of peanut butter. Datura wrightii, for some reason, is not as common in landscapes as D. metel and D. inoxia. It is much like D. inoxia, though, except for the fact that the flowers are slightly larger than those of inoxia and they frequently have a violet or lavender tinge. I wish that I had a picture of an inoxia bloom next to a wrightii, because the difference in overall appearance is difficult to describe.
Here's a couple wrightii (or inoxia, can't really tell from the pod) seed pods:
http://museum.utep.edu/chih/plantimage2/daturawrightii1.jpg
http://www.timetotrack.com/jay/jimson4.jpg

Consider also that the common names of Datura are interchanged frequently, and many seed companies neglect to differentiate between D. metel var. metel and D. inoxia, referring to their plants only by their common name. I have seen catalogs with the same variety listed multiple times under different names and different prices. You'd be surprised at how many synonyms there are for Datura metel var. fastuosa (double/triple purple).

If you could remember the characteristics of the seed pod, that would be helpful in determining your mystery plant.

Anyone on here have double flower datura, if so I'm very interested in a few seeds. Ty