The Collaborative International Dictionary of English v.0.48:

Aphyllous \Aph"yl*lous\, a. [Gr. ?; 'a priv. + ? leaf.] (Bot.)
   Destitute of leaves, as the broom rape, certain
   euphorbiaceous plants, etc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

aphyllous
    adj 1: having no leaves