1. Petunia integrifolia (Hook.) Schinz et Thell. (syn.: P. violacea Lindl.) (S-Am.) – An exceptional and ephemeral alien. Recorded only once with certainty on a dump in Roeselare in 2005 but possibly overlooked.
Petunia integrifolia has a small, rather unshowy corolla and is not very appropriate for cultivation. It was formerly recorded as a grain alien near mills in the Netherlands (van Ooststroom & Reichgelt 1966) and the only Belgian record is possibly also rather associated with cereals (incl. birdseed).
The morphology-based taxonomy in this group does not reflect its evolutionary history, and revision of its species limits should incorporate the distribution of the genetic diversity (Longo & al. 2014). Segatto & al. (2014) suggested that Petunia interior T. Ando & G. Hashim., one of the microspecies of the P. integrifolia group, probably is the purple ancestor of this hybrid.
Longo D., Lorenz-Lemke A.P., Mäder G., Bonatto S.L. & Freitas L.B. (2014) Phylogeography of the Petunia integrifolia complex in southern Brazil. Bot. J. Linn. Soc. 174(2): 199-213.
Segatto A.L.A., Ramos-Fregonezi A.M.C., Bonatto S.L.. & Freitas L.B. (2014) Molecular insights into the purple-flowered ancestor of garden petunias. Am. J. Bot. 101(1): 119-127.
Van Ooststroom S.J. & Reichgelt Th.J. (1966) Solanaceae-Orobanchaceae. In: van Ooststroom S.J. & Van der Veen R. a.o. (eds.), Flora Neerlandica, vol. 4(2). KNBV, Amsterdam: 65 p.