Circle of the Treant

From publisher blurb:

Druids of the Circle of the Treant are deeply connected with the awakened trees that dwell in ancient forests. Strong and steadfast, druids of this circle serve as forest guardians, assuming a mighty wildwood form to protect Treants meditating through a long cycle of seasons. As their connection deepens, the druid acquires tree-like features, forming bark across its skin as its hair slowly turns into foliage.