I'm pretty confident about the ID on this one. I used two different books to key it out, and in both cases ended up with the same species ID. Identifying characteristics: Leaf margins toothed, capsules ridged/four-sided and >1.5x as long as wide, directly attached to stalk without a disk, leaves sheathing sporophytes in different color than other leaves, found in deciduous forest habitat
On soil in maple-beech forest.
Lamellae cells thick walled and entire in profile.