My YA fantasy series has a culture that communicates with their goddess and each other by using flowers and their cultural meanings. I’ve been asked if I invented that idea. Well, the goddess part, yes, but the flower part, no. Here are some articles you can read about the well-established practice of sending messages with flowers, including a list of meanings.
You might notice a few discrepancies between the websites, or between the sites and my books. In that case, please consider my books to use the Darendrakar version of the flower language, translated to the best of my ability.
Agrimony (go look it up),