I know that daylillies are an ingredient in hot and sour soup. They're called "golden needles"...

From Wikipedia:

The flowers of some species are edible and are used in Chinese cuisine. They are sold (fresh or dried) in Asian markets as gum jum or golden needles (éé in Chinese; pinyin: jÄ«nzhÄn) or yellow flower vegetables (é»è±è in Chinese; pinyin: huánghuÄcà i). They are used in hot and sour soup, daylily soup (ééè±æ¹¯), Buddha's delight, and moo shu pork. The young green leaves and the tubers of some (but not all[citation needed]) species are also edible. The plant has also been used for medicinal purposes. Care must be used as some species of lilies can be toxic.

Hope that helps!

Here is a link that might be useful: Daylily @ Wikipedia