Vicki, I believe the old fashioned petunia is known scientifically as
Petunia × hybrida. The identity of the original parents is not certain, but a good guess is that they were
P. axillaris and
P. integrifolia.
axillaris
integrifolia
If you're interested, here is an article on petunias I published some time ago:
http://garden.org/ideas/manage...