Carex concinna is a tufted perennial sedge with tightly clustered spikes of bi-colored flowers. This species occurs in well-drained spruce forests, river terraces, and warm, open slopes mostly in the lowlands but extending into the lower alpine zone in Denali. The thin, arching stem grows 10-20 cm tall with purplish basal sheaths. Leaves are basal, flat, dark green, 1-3 mm wide and about half the height of the stem. Stems lack a subtendingbract. The inflorescence is tightly clustered with a single terminal staminatespike, and 2-3 sessile, lateral pistillatespikes. The pistillate scales are reddish-brown with a greenish mid-rib and transparent-ciliate margins. The green perigynia are twice as long as scales (leading to a bicolored appearance), three-angled, and distinctly pubescent. The fruits are 3-styled achenes. The sheathing bracts and pubescent perigynia help distinguish this species from other sedges.
Carex concinna is perennial, semi-evergreen, and is one of the first sedges to flower in Denali.
Carex concinna is restricted to North America where it occurs from Alaska across Canada and ranges southwards down the Rocky Mountains and into the Pacific Northwest, and also eastward and into Wisconsin and Michigan. Carex concinna occurs primarily in eastern and northern Alaska, but ranges into sites on the Seward Peninsula, and also into the southeastern panhandle in widely scattered localities. In Denali, C. concinna occurs scattered well-drained sites across the park, most frequently north of the Alaska Range crest, but with isolated stations to the south also.
Carex concinna is primarily a low elevation species uncommonly occurring in Denali from 134 m to 979 m, with an average plot elevation of 525. This species most frequently occurs in plots with an elevation between 300-500 m. This species shows no significant preference for plot aspect or inclination, although the average plot slope is 4 degrees.