One of my favorite flowers that was also historically used by Gregor Mendel, the Augustinian monk, during his study of genetics is the sweet pea. 

The sweet pea is an annual fragrant, butterfly-shaped, climbing herb. Its scientific name is Lathyrus odaratus meaning, fragrant pea. It has an intense, orange-jasmine-honey scent and is a native plant of Italy. Sweet peas come in a variety of colors including white, pink, reds, blues, purples, bicolors, strips and reverse bicolors.

This sweetly scented ornamental is not edible because it is toxic if ingested in large quantities, but is treasured because of their longevity, colorfulness, and fragrance. Finally, in many places, it is symbolic of blissful pleasure.