I have solid white datura (S. wrightii) and double purple-white datura (D. metel) growing in the same bed. The white variety volunteered and has set many seed pods, some of which have already turned brown and split. The purples, which were winter sown, don't have any pods, just wilted blossoms. Does that mean the purples haven't pollinated and I won't get any seeds? Bees, hummingbird moths, and other pollinators are all over both plants. Advice, anyone?

Thanks in advance