- any of several common North American wildflowers of several families (esp. genera Thunbergia and Rudbeckia of the acanthus and composite families) having flowers with yellow petals or bracts around a dark center
- the flower of any of these plants
Origin of black-eyed Susanso named from the dark center of the flower
- Any of several North American herbs of the genus Rudbeckia in the composite family, especially R. hirta, having hairy stems and leaves and showy flower heads with orange-yellow rays and dark purple or brown centers.
- A tropical African twining herb (Thunbergia alata) cultivated for its showy, usually yellow to orange tubular flowers with dark purple centers.