arbuscle

noun4

1. •
   A plant midway in height between a shrub and a tree; a dwarf tree.

   • Ar′boret or arbus′cle. A little tree. — 1853
2. •
   A branched hypha in some fungi.

   • The hyphae of the arbuscle, which are finely ramified and form a floccose mass, soon lose their individuality and make a structureless granular and gummy conglomeration […] — 1956
3. •
   The site at which a symbiotic fungus attaches to the roots of a plant and exchanges nutrients, etc., with it.
4. •
   A clump of feather-like cilia (hairlike structures).