The Collaborative International Dictionary of English v.0.48:

Genista \Ge*nis"ta\, prop. n. [L., broom.] (Bot.)
   A genus of plants including the common broom of Western
   Europe.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Genista
    n 1: chiefly deciduous shrubs or small trees of Mediterranean
         area and western Asia: broom [syn: Genista, genus
         Genista]