Abstract
Three vegetative and 6 floral characters of P. axillaris (Lam.) B.S.P., P. inflata Fries, P. parodii W.C.S. and P. violacea Lindl., their reciprocal hybrids and 14 P. hybrida Vilm. cultivars were measured and comparisons made to gain further information on the origin of the garden petunia. Evaluation of the floristic data plus flower color requirements and breeding behavior excluded P. parodii as a possible ancestor. P. axillaris crossed with P. inflata produced hybrids that may account for the range of variability observed in the cultivars, flower color array and introduction of self-incompatability genes.