It's beneath a tree's inner bark, 7 letters
Soft trunk part, 7 letters
Tree-trunk layer, 7 letters
Whence maple syrup, 7 letters
Newly formed outer wood lying between the cambium and the heartwood of a tree or woody plant, 7 letters
Usually light colored, 7 letters
Active in water conduction, 7 letters
Permeable parts of trees, 8 letters