I was reading "The Secret Life of Oscar Wilde" the other day (well, actually, still am), and at one point, it discussed his involvement in the Aesthetes movement. They had the lily as their quintessential symbol.
I was wondering whether that's the reason why the emblem for Dibella's cult is also a white lily, and her order is called the Order of the Lily? Okay, perhaps its not very prominent in Morrowind, but I do recall them from my days in Daggerfall...
Just a thought, really... What do you think?

I don't remember any in-game texts that deal with this topic, but this might be able to help you. It is a list of all of the mythological and religious properties of the lily as well as a history of the lily trade.
Also, Rachel Weisz plays a character named Lily in Confidence. I'm in love with her.