Source : Webster's Revised Unabridged Dictionary (1913)

Vitis \Vi"tis\, n. [L., a vine.] (Bot.)
   A genus of plants including all true grapevines.

Source : WordNet®

Vitis
     n : the type genus of the family Vitaceae; woody vines with
         simple leaves and small flowers; includes a wide variety
         of grapes [syn: {genus Vitis}]