Source : Webster's Revised Unabridged Dictionary (1913)

Rudbeckia \Rud*beck"i*a\, n. [NL. So named after Olaf Rudebeck,
   a Swedish botanist.] (Bot.)
   A genus of composite plants, the coneflowers, consisting of
   perennial herbs with showy pedunculate heads, having a
   hemispherical involucre, sterile ray flowers, and a conical
   chaffy receptacle. There are about thirty species,
   exclusively North American. {Rudbeckia hirta}, the black-eyed
   Susan, is a common weed in meadows.

Source : WordNet®

Rudbeckia
     n : North American perennial herbs with showy cone-shaped flower
         heads [syn: {genus Rudbeckia}]