The Great Tree is the massive tree I described earlier, with a slight change.
Saplings are vaguely humanoid plant-like creatures with the ability to change/adapt their growth. They can eat meat or vegetable matter, as well as 'rooting' to gain sustenance from sunlight/other powerful light sources, which they do for most of the day, as a form of 'sleeping'. They have good night vision, and are primarily nocturnal for the reason of needing to root during the day. They are slower, sturdier, and slightly stronger than humans, and both live longer and think slightly slower, on a longer timescale. Finally, they have a special relationship with the Great Trees that are their home. All Saplings are 'male'. All Great Trees are 'female'. While the Saplings can live away from the Great Trees, they (mostly) cannot reproduce without them. New Saplings effectively bud from 'womb-flowers', which are pollinated by the Saplings. Other creatures could theoretically serve as pollinators, but it has not been observed to happen, and it would still just produce Saplings. Most Saplings, once mature, stand between 7 to 10 feet tall, and weigh between 200 to 450 pounds. Their skin is similar to wood or bark, and can vary greatly, though it tends to be similar to the bark of the tree they were born of. The 'womb-flowers'(as there are many kinds of flower upon a Great Tree) of the Great Tree also happen to maintain genetic diversity, even though they come from the same Great Tree. How, few are quite sure. Saplings usually have vines, flowers, or leaves for a 'hair' analogue, though it is not restricted or necessarily on their head, especially as they are not always humanoid in form.
Great Trees can reproduce to make other Great Trees, but it is a supremely rare occurrence. After all, every Great Tree has a divine spark of Power within it, blessed by their god. To ensure the Tree's survival while it grows, which can take centuries before it reaches maturity, a community of Saplings will accompany the seed on what amounts to a Holy Mission. This seems to be one of the few circumstances that can enable Saplings to seemingly reproduce on their own, in order to provide protection to the growing Great Tree. Some theorize Great Trees to be sentient or even sapient, given their ability to adapt to stimuli, and defend themselves and their charges.