Answer:
Long and think, red within, with a nail at the end.
As I walked along the path I saw something with four fingers and one thumb, but it was not flesh, fish, bone or fowl.
What runs around all day. Then lies under the bed. With its tongue hanging out?
Two little holes in the side of a hill. Just as you come to the cherry-red mill.
A precious stone, as clear as diamond. Seek it out whilst the sun's near the horizon. Though you can walk on water with its power, Try to keep it, and it'll vanish within an hour.
It produces a flower but it is not its fruitΝΎ it produces branches which are its fruit.