Flowers have a long history of symbolism that you can incorporate into your writing to give subtext.
Symbolism varies between cultures and customs, and these particular examples come from Victorian Era Britain. You'll find examples of this symbolism in many well-known novels of the era!
Black-eyed Susan: Justice
Yellow Carnation: Rejection
Daffodil: Unrivalled love
Daisy: Innocence, loyalty
Geranium: Folly, stupidity
Gladiolus: Integrity, strength
Hibiscus: Delicate beauty
Honeysuckle: Bonds of love
Hydrangea: Frigid, heartless
Iris: Faith, trust, wisdom
White Jasmine: Amiability
Tiger Lily: Wealth, pride
Lily-of-the-valley: Sweetness, humility
Lotus: Enlightenment, rebirth
Marigold: Grief, jealousy
Nasturtium: Patriotism, conquest
Peony: Bashfulness, shame
Yellow Rose: Jealously, infidelity
Snapdragon: Deception, grace
Violet: Watchfulness, modesty
Zinnia: Absent, affection