Flowers are the sex organs of plants 😉  – designed to attract the birds and insects to help with cross-polination.
The language of flowers is ancient. To quote Wikipedia – “Meaning has been attributed to flowers for thousands of years, and some form of floriography has been practiced in traditional cultures throughout Europe, Asia, and the Middle East”.
Roses are traditionally ascribed different meanings, based on their colour: red for romantic love, yellow for friendship and joy, white for innocence and new beginnings…
If you are interested in the symbolic meaning of specific flowers for your wedding, you might want to do some internet research of your own.
Flowers