Sowing Discord is based on the Victorian language of flowers – all of the flower meanings come from 19th century lists of flowers and their meanings. Lots of cultures have their own language of flowers, but the Victorian English one used in Sowing Discord was brought to Europe from Turkey in the early 18th century by Lady Mary Montagu, the wife of the British ambassador to Turkey. The European language of flowers had a bit of a slow start, and first became popular in France when Madame Charlotte de la Tour published La Langage des Fleurs in 1819. Most of the English floral dictionaries are based on her work, although later books included more complete lists of flowers.
The rules of Sowing Discord also come from the language of flowers. Here are some of the rules for making bouquets from The Language of Flowers and Floral Conversation (1875) :
Rule 1. —If a flower be given reversed, its original signification is understood to be contradicted, and the opposite meaning to be implied.
Rule 4. — The meaning of a flower may be used as a noun, as a verb or as an adverb, as may be convenient. Example: — The Flowering Almond expresses hope, but in connection with some other flower it may be hopefully or to hope in any tense.
And if you think that the Victorians were above cattiness in their bouquet giving, think again. Here are some sample bouquets given by The National Encyclopedia of Business and Social Forms (1879):
Your insincerity and avarice make me hate you.
Cherry Blossom or Foxglove: Insincerity. Scarlet Auricula: Avarice. Turk’s Cap: Hatred.
Your frivolity and malevolence will cause you to be forsaken by all.
London Pride: Frivolity. Lobelia: Malevolence. Laburnum: Forsaken.
If you’d like to read more about the language of flowers, there are many Victorian guides available at the Internet Archive. One of my favourites is The Language of Flowers and Floral Conversation (1875) by Charles W Seelye.