I read that some seedlings of Mexican Petunia cultivars resemble the non-cultivar, wild-type form of Mexican Petunia.

Maybe this would be a bigger problem for the white and pink cultivars of Mexican Petunia, but not the Morado Chi cultivar, as it already resembles wild-type, I think.

Hi Gav65,
I grow the dwarf type. Actually they grow themselves. Spreading through out the garden. They look beautiful. Even though, luckily they duplicate as dwarf, sometimes they revert back to tall, which I pull mostly. Occasionally I get a pink dwarf, which I like.
I slipped into to calling them Mexican popping plants, because when it rains or you water them, the seeds pop across the yard. I remember once sitting in the yard. I heard a drop and felt a seed hit my cheek from about 4 feet away. The first new plant I got from seed was 12 feet from the parent. I thought the root traveled that far, not knowing that the seeds pop that far. At this time of the year they are one of the prettiest plants in my garden. Sorry I did not answer your question.