In almost all kinds of dense to open, moist to dry forests and thickets, particularly characteristic of beech-maple stands, but also in cedar swamps and mixed forests. Very local southward.

The pistillate scales, except for the green along the midvein, are very pale and translucent, giving a characteristic silvery appearance to the inflorescence.

Like a number of other woodland Carex, C. deweyana culms, relatively short and ± erect while flowering, elongate considerably as the fruit matures, at full maturity lying prostrate radiating in all directions from the clump, thus facilitating making local patches in woodlands. Chester Dewey (1863), noting the appearance of this species around Rochester, New York, waxed effusively that he found it "...in one dense matted oval turf of three feet in length and two in breadth, with the host of culms (hundreds at least) lying prostrate in all directions, light green; a plat of vegetable life more beautiful had never occurred to me."