Sedges are like grass, but fancy. And Merten's sedge is exceptionally fancy. Check out those big fluffy nodding flower heads that arch up to 3 ft above thick lush leaves. Another bonus, this sedge will grow in the shade! Bright shade, not deep shade. Think of the understory of an moist open forest. It needs a fair amount of moisture and is a good candidate for a rain garden or sprinkler overspray.
Use it to provide structure to a garden or as a lush backdrop for for flowering plants such as cutleaf coneflower, aspen daisy, lyall's angelica, baneberry, nettleleaf giant hyssop, and meadow-rue.
Image credit: Franz Xaver, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons