Bajoran lilacs are a flowering plant found on Bajor.
Lilacs were Kira Meru's favorite flower, something which Kira Taban told his daughter Nerys about. In 2346, Skrain Dukat gave her a bouquet of lilacs. In 2374, on the day that would have been her mother's sixtieth birthday, Kira had Quark obtain some lilacs to honor her mother's memory. (DS9 episode: "Wrongs Darker Than Death or Night")
In 2375, Benjamin Sisko gave Kasidy Yates a bouquet of lilacs to apologise for using his influence to get her leave. (DS9 episode: "The Changing Face of Evil")
By the following year, Kasidy had planted lilacs in the garden of her home on Bajor. She planned to fill vases with them and place them around the house. (DS9 novel: This Gray Spirit)