These arrangements symbolize romance, new or old. And frequently star roses. carnations, and babies breath.
These arrangements symbolize joy and happiness. A few reappearing flowers are tulips, daffodils, and irises.
These arrangement symbolize grief, and are a gentle way to vent. A few common flowers are babies breath, chamomile, forget-me-nots, and hyacinth.
Flowers and plants have had symbolism as long as symbolism has been a concept. And really gained popularity among the Victorians- they would go as far as to have an entire dialogue without a single spoken word!
And though it has since fallen out of popularity, flower symbolism (or floriography) is still a simple and sweet way to communicate to someone, and to let them know in a thoughtful way how you feel about them.