exorhizal

from The Collaborative International Dictionary of English v.0.48

Exorhizal \Ex`o*rhi"zal\, Exorhizous \Ex`o*rhi`zous\, a. (Bot.)
   Having a radicle which is not inclosed by the cotyledons or
   plumule; of or relating to an exorhiza.
   [1913 Webster]