In NEI they have no recipe. Their seeds don't have recipe as well. Breaking grass seems to produce only Vanilla and Witchery seeds.
Lilies are enabled in the config. If they have no recipe then they were most likely disabled by the modpack. Can always try the bonemeal like john said.
I have found them in the wild. They are just random. I know when you walk over one it turns you in another direction. Check heavily greened areas like forests or jungle.
Not in the configs, Mod pack devs did not add a recipe for them. So at the moment not able to be acquired. I'll go poke the devs.