A Primitive Type of Dahlia
The wild dahlias are sunflower-like plants that scarcely suggest the familiar cultivated dahlias of the flower garden. It will be seen, however, that the primitive type here shown manifests a tendency to variation in form of the "petals" (properly ray flowers), suggesting possibilities of development.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 9 Chapter 7