Field Bindweed (Creeping Jenny) is a viney weed that forms a network of runners under the ground, and shoots grow to the surface every few inches along the runners. It thereby produces patches which consist entirely of an individual plant. The phenotype is the same for the entire patch. Each patch has its own color of flowers, somewhere between purple and white.

The variations in flower color must be phenotypic rather than genotypic, because natural selection does not allow different genotypes to occupy the same niche, beyond transitory effects.

Flowers are identical within a patch, which shows that environmental effects do not influence the appearance of the flowers. Flowers stay the same throughout the season, and from season to season, since the weed is a perennial.

Here are larger clusters of heavy purple, medium purple and white. It shows that all flowers within a patch are identical with no visible variations between them.

These cannot be different genotypes. Different genotypes will never occupy the same niche. One will always prevail over the others.
 
Echinacea Phenotypes