Day Lily is a name applied also to species of Hemerocallis, which are yellow-flowered lilies.
Another very poor combination that is in my garden, much to my sorrow, is Hemerocallis and siberica iris.
This day lily (Hemerocallis fulva) is sister to the familiar and showy lemon lily of old gardens (Hemerocallis flava).
Hemerocallis fulva and flava, interchanging by bud-variation, i. 386.