The hydrangea’s blossom in the shape of a globe has long attracted many admirers. Japanese legend has it that the emperor once sent a bouquet of hydrangeas to apologize to the family of a girl he loved, his only recorded apology. This radiant flower has come to symbolize earnestness, and is ideal for communicating any heartfelt emotion, from joy to grief.
For many years, the lily was the most exotic flower available. The tiger lily’s strange and alluring dots and stripes promised adventure. This adventure was often thought to lead to wealth and prosperity. Even today, sending a fresh bouquet of lilies communicates a wish for happiness, excitement, and prosperity.
Love is the flower you've got to let grow (quote and images from google)