1998 Volume 48 Issue 2 Pages 173-185
To clarify morphological intergradation between two subspecies of Petunia axillaris, floral morphological characters were studied on live plants grown from seeds collected from 102 localities in Uruguay. Five discriminant functions were calculated by stepwise discriminant analysis using typical individuals of the two subspecies (from 12 localities of subsp. axillaris and from 16 localities of subsp. parodii). Mean values of floral characters taken from individuals from 102 localities were substituted into these five functions to predict subspecies. Plants from some localities were predicted inconsistently or doubtfully by respective functions and were regarded as intermediate. The results confirmed our previous reports, but the distribution of the two subspecies and their intermediate forms was inferred with more detail and clarity. Two subspecies of Petunia axillads occurred separately and the border between the two taxa roughly corresponds to the Rio Negro river. The localities of intermediate forms were mostly distributed in the area parallel to the Rio Negro and on the shore of the Rio de la Plata.
