The Flower Parts.

Many flower designs include nectar guides for the various polinators.
Nectar guides can be a series of dots as in the Mimulas family.
Nectar guides in violets are usually radiating lines.
Many have simple nectar guide lines.
Many do not need nectar guides as they are pollenated by moths, like the Evening Primrose.
Fringed ray flower of the Blue Chicory