The Elderly Tree is a tree that likes silence
The tree is in the middle of the indoor garden of the 5th Floor. If you talk to the tree, it'll ask you if you want something. And since there isn't anything you need, it then says "Well I don't need anything from you. Be silent"
Talking to the tree again, it remembers that there's one thing and that is to don't disturb the keeper of time. (The grandfather clock in the yellow flower's room)
He thinks that the Keeper of Time is annoying and wants you to get rid of him. To get rid of the keeper of time, you need to pour water on the grandfather clock in the yellow flowers' room. (You get the water from the Skull Puzzle). After the keeper of time is gone, the Elderly Tree will be able to sleep shakes its leaves before, making a branch fall down. With the branch you can get down the Green Candle from The Greenery. The Green Candle is needed to progress through the game.
- When the garden turns red, every plant dies, including the Elderly Tree.
- In The Diary of Ellen manga, Ellen mentions that she recognized feel that the tree is familiar. This likely in reference to the tree in the garden where she buried the black cat.