Genesis 2:9, How many trees in the Garden of Eden?

And out of the ground the LORD God made every tree grow that is pleasant to the sight and good for food. The tree of life was also in the midst of the garden, and the tree of the knowledge of good and evil.
//Lots of trees in the garden, but two were special, the two that were planted in the middle of the garden … or was it just a single tree? God refers to only one as he instructs Adam:
And the LORD God commanded the man, "You are free to eat from any tree in the garden; but you must not eat from the tree of the knowledge of good and evil, for when you eat of it you will surely die." –Genesis 2:16-17
Later, the serpent tempts Eve, asking her what she is allowed to eat. She mentions only the one “in the middle of the garden”:
The woman said to the serpent, "We may eat fruit from the trees in the garden, but God did say, 'You must not eat fruit from the tree that is in the middle of the garden, and you must not touch it, or you will die.'" –Genesis 3:2-3
Could the two trees have been one and the same? When Revelation is penned promising a new Eden, why is there only one great tree there? Is the tree of life also the tree of knowledge? After all, what did Adam and Eve learn to do with their new knowledge? They made life.
Adam lay with his wife Eve, and she became pregnant and gave birth to Cain. –Genesis 4:1