Realism Questions

[FlawlessHappiness]

Well, the first thing that might start grow there is grass/moss. The creepers will also be useful here.
Afterwards, different bigger plants might've started growing, such as ferns.
Maybe a tree have found it's way in. There is a big tree model thing, in the original amnesia. This tree would probably seek the light the most. Therefore it reaches for the hole in the roof.

Remember. Plants need light to be able to grow. Not just water. So, plants will be in light. Mushrooms though... They could grow anywhere, but would probably grow together in groups. Maybe in corners, and such.