A culture of dryads has a strange death tradition. When a dryad dies there's usually a medic, or better say a "shaman" that rips a strange looking organ or gland off their head. The gland, shiny and the size of a hand, is then grafted into a tree.
After several centuries the tree is able to finally release a fully grown child using only the gland from the old dead dryad and minerals from the ground. The dryad will have most of their memories intact after being reborn.
I'm not asking if this is realistic, or plausible. I'm asking if the "gland" or any organ can force the tree to get the needed minerals off the ground and slowly build a humanoid child over the course of centuries.
Why this question? I wanted to make dryads immortal while avoiding over overpopulation and other problems related to immortality by allowing them to die and come back as the same entity but younger after some centuries.
Question: Can humanoids be born (reborn) from a tree?