Source : Webster's Revised Unabridged Dictionary (1913)

Epiphyllum \Ep`i*phyl"lum\, n. [NL.] (Bot.)
   A genus of cactaceous plants having flattened, jointed stems,
   and petals united in a tube. The flowers are very showy, and
   several species are in cultivation.

Source : WordNet®

epiphyllum
     n : any cactus of the genus Epiphyllum having flattened jointed
         irregularly branching stems and showy tubular flowers
         [syn: {orchid cactus}]