black-eyed Susan or yellow daisy, North American daisylike wildflower (Rudbeckia hirta) of the family Asteraceae (aster family) with yellow rays and a dark brown center. It is a weedy biennial or annual and grows in dry places. The black-eyed Susan and the other rudbeckias are also called yellow coneflowers. The most widely cultivated is the golden glow (R. laciniata hortensia), a tall double-blossomed perennial. Black-eyed Susans are classified in the division Magnoliophyta, class Magnoliopsida, order Asterales, family Asteraceae.