The daylily (hemerocallis) and the tiger lily (lilium lancifolium) are separate flowers. In particular, lilies (including tiger lilies) have a completely different stem-and-leaf shape from daylilies.

http://www.daylilies.org/ahs/AHSfaq1.html#whatis: "The daylily is a member of the lily family Liliaceae, as are such plants as onions and hyacinths. Whereas lilies are in the plant genus Lilium, daylilies are in the genus Hemerocallis."

day lilly: http://www.ofts.com/photo/gallery.html
tiger lily: http://www.holoweb.com/cannon/tigerlil.htm