Tendency To Variation in Dahlias
The wild dahlia evidently had unusual propensity to vary; otherwise it would hardly have been possible to develop the extraordinarily complex flowers that are now to be seen in our gardens within the comparatively short period of time since the dahlia was brought under cultivation. Here we see illustrated the tendency to variation even among flowers growing from the same stem.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 9 Chapter 7