Plexus /(?)/

pl. Plexus, Plexuses

1. A network of vessels, nerves, or fibers. (Anat.)
2. The system of equations required for the complete expression of the relations which exist between a set of quantities. (Math.)
3. A network; an intricate or interwoven combination of elements or parts in a coherent structure.

   In the perception of a tree the reference to an object is circumscribed and directed by a plexus of visual and other presentations.