Disturbed forests and forest edges, especially along trails. This Eurasian species, first collected in Emmet Co. in 2007 by K. Gyekis, is very locally frequent in some parts of Ontario, and can be expected to increase its range.

Carex sylvatica is quite like C. arctata in superficial appearance, but forms dense, large clumps lacking the reddish purple bases of C. arctata (and all other species of sect. Hymenochlaenae, except for the distinctive C. sprengelii). The perigynia are very persistent and can be seen on the plants as late as early November unlike all other similar Michigan species.