Daylily nutrient values are not well documented. Below are a couple of values that were found. One might expect variation in these values depending on species or variety of daylily as well as age of the harvested material.
Protein and Vitamin Content of Daylily Buds (from Erhardt: Daylilies 1992)
Vitamin C : 43 mg/100g
Vitamin A : 983 IU
Protein % : 3.1
Vitamin C : 19 mg/100g
Vitamin A : 630 IU
Protein % : 2.2
The information below was taken from a now defunct website: Weed Nutrition.
It's assumed that this refers to dried flowers of Hemerocallis fulva.
Day Lily (per 100g) Hemerocallis fulva
Vitamin A 3,000 I.U.
Vitamin C 88mg