The tag alias #69282 tree_root -> roots is pending approval.
Reason: If a tree is visible, it should be tagged tree. Otherwise, there's nothing differentiating tree roots from non-tree roots, so it should only be tagged roots, not tree_root.
Relevant searches: tree_root -tree, tree_root tree
Note: we do have tree_trunk, but this is to differentiate from unrelated (animal) trunk. There's no such tag for a "non-tree" plant trunk. It's debatable if maybe all roots are tree roots, but symbolically they're used without actual trees in-frame or as part of the picture pretty often (roots -tree), so I don't think it makes sense to do the reverse of this alias (and then have tree_root implicate tree, like tree_trunk implicates tree).
Updated