1. 
[syn: arboreal, arboreous, arborescent, arboresque, arboriform, dendriform, dendroid, dendroidal, treelike, tree-shaped]
The Collaborative International Dictionary of English v.0.48:
Arborescent \Ar`bo*res"cent\, a. [L. arborescens, p. pr. of
   arborescere to become a tree, fr. arbor tree.]
   Resembling a tree; becoming woody in stalk; dendritic; having
   crystallizations disposed like the branches and twigs of a
   tree. "Arborescent hollyhocks." --Evelyn.
   [1913 Webster]
WordNet (r) 3.0 (2006):
arborescent
    adj 1: resembling a tree in form and branching structure;
           "arborescent coral found off the coast of Bermuda";
           "dendriform sponges" [syn: arboreal, arboreous,
           arborescent, arboresque, arboriform, dendriform,
           dendroid, dendroidal, treelike, tree-shaped]