William Blake's Book of Urizen and mushroom symbols

Book of Urizen

   William Blake’s, Book of Urizen represents Blake’s attempt at rewriting the Bible, and incorporating Gnostic ideals.  Rather than try to interpret the work, I just want to examine the art for their mushroom implications.  Take the title page for example; it has an old man, sitting beneath a tree, writing a book.  In the background, are the two-tablet like tombstones, which represent Moses’ Ten Commandments.  These two tablets form the silhouette of a mushroom.  In addition, Urizen is sitting under a tree.  Is this the tree of knowledge of good and evil?  Also, many of Blake’s works are framed as a mushroom; the canopy of the trees forms the cap, and the two tablets and the man form the stalk.

Object 4 of Urizen has Urizen reading a rainbow colored book, and his head appearing to emanate light.  His arms are outstretched like the cap of a mushroom.

Object 5 is of an upside-down figure, entwined with a snake, with arms outstretched; Blake’s version of the staff of Asclepius.  The snake is a symbol for the serpent from the Garden of Eden.  And it appears underground, representing the mycelium of the mushroom.

http://en.wikipedia.org/wiki/Asclepius

Object 15 has a bent over figure, atop a red globe.  I suspect the red globe to be the mushroom cap of the Amanita muscaria.

Object 20, shows Urizen chained, and mostly white.  Emanating from his head, appears to be a red light.  His body is the white stalk of the mushroom, which meets the red cap of the mushroom. 

Object 21  has Urizen walking and carrying the red globe.  He is clothed in white, while the globe is red.  

     These are just the obvious examples.