The Collaborative International Dictionary of English v.0.48:

phylloclade \phylloclade\, phyllocladium \phyl`lo*cla"di*um\,
   n.; pl. Phyllocladia. [NL., fr. Gr. fy`llon a leaf +
   kla`dos a sprout.] (Bot.)
   A flattened stem or branch which more or less resembles a
   leaf, and performs the function of a leaf as regards
   respiration and assimilation.

   Syn: cladode, cladophyll, phylloclad.
        [1913 Webster + WordNet 1.5]

WordNet (r) 3.0 (2006):

phylloclade
    n 1: a flattened stem resembling and functioning as a leaf [syn:
         cladode, cladophyll, phylloclad, phylloclade]