The Collaborative International Dictionary of English v.0.48:

Antidromous \An*tid"ro*mous\ ([a^]n*t[i^]d"r[-o]*m[u^]s), a.
   [Pref. anti- + Gr. dro`mos a running.] (Bot.)
   Changing the direction in the spiral sequence of leaves on a
   stem.
   [1913 Webster]