I posted this on the Texas Forum, but it's funny enough to share here, too.

A neighbor brought me some seeds from his white datura (moonflower).

He said that he had bought seeds for a double purple & a yellow, but they never germinated.

I wondered if it was because they were foo-foo hybrids while the white ones were species type.

He said:
"You mean the purple ones & the yellow ones are purebred pedigree pigs & the white ones are wild boars?"

exactly!