[ he holds his hands up. He can tell the other is already worrying, overcalculating the new knowledge in his head, in his hands. He'll even stop to put a hand on top of Kni's head. ]

I'm honestly not sure--but let me reassure you of something.
My hair only turned black for the first time when I output a lot of energy at one time, as I just mentioned. There wasn't a single black hair before that.

So, I figure, if I don't use my powers at such a volume, I'll live for a really, really long time.

Honestly, I'm really of the opinion that I never have to use my plant powers. Not with the magic that exists in this world being less... detrimental to my life span.

So don't worry.
You'll not lose me anytime soon.