When I said mutation I was referring to a mutation of the Ipomoea alba .. the black seed has absolutely NOTHING to do with the Stargazer Lily. The lily pollen cannot fertilize the Moonvine flower. Your black seed is probably a mutation which occurs from time to time with plants in their own genus and species.
A good example is the El Capitolio Tropical Hibiscus. The flowers are usually red - known as Bloody Mary, but a mutation aka 'sport' occurred on a red flowering plant creating an orange flower and the branch with orange flowers was cut off and rooted and the sport is called Tequila Sunrise. As you can see in the picture, the form of the flowers are identical .. only the colors are different. It's not a hybrid.
