Source : Webster's Revised Unabridged Dictionary (1913)

Night-blooming \Night"-bloom`ing\, a.
   Blooming in the night.

   {Night-blooming cereus}. (Bot.) See Note under {Cereus}.

Source : WordNet®

night-blooming cereus
     n 1: any of several night-blooming cacti of the genus
          Selenicereus
     2: any of several cacti of the genus Hylocereus
     3: any of several cacti of the genus Cereus