The Collaborative International Dictionary of English v.0.48:

Lichenic \Li*chen"ic\ (l[-i]*k[e^]n"[i^]k), a.
   Of, pertaining to, or obtained from, lichens.
   [1913 Webster]

   Lichenic acid.
   (a) An organic acid, C14H24O3, obtained from Iceland moss.
   (b) An old name of fumaric acid.
       [1913 Webster]