I mean, it's right there in the screen couplet:

The tree waits for some rain / To end his suffering and pain

Clearly it's not talking about the sort of rain we already have, as that comes and goes and the tree remains exactly as it was, so nothing has "ended"

Anyone have any thoughts on this?

 

[inspired from a conversation with Ungod]

 

A question, if I may:

Were there any appreciable difference betwixt its suffering when skies are clear, and when rain should fall?

I mean, if so we should be making it rain as much as possible.

My theory together with Ungod is that the tree is burning, and that constitutes its "life".  (See also the clue on "the blooming of bob" for more about the alive-ness of the tree.)

  For lack of foliage (in contrast to the trees in MB) it simply burns at its core/s, similar to the necrovion trees except straight.  (this actual puts it in a unique position to "ensure the fruit")

Rain would kill it, thus ending its core-burning pain, but the pain is actually worthwhile for him if he still might bloom.

You can actually see some of the smoke from the branches if you look closely.

26 minutes ago, klatdees said:

I mean, if so we should be making it rain as much as possible.

I see, that makes sense. Guardians of Bob should have rain spells

Spoiler

What the tree symbolizes (according to our theory) also comes with a great deal of suffering, almost like burning. Rain that washes everything away, that reverts built castles to mud, is capable of bringing relief. I like this interpretation, even if it's the wrong one.

 

In that case, "rain" may be vital energy, "heat" or the thing that keeps the tree alive... He needs that energy to bloom and will be in sorrow if not have it... Provide that energy and you will be alleviating his sorrow...