Carex nigricans is a species of sedge known by the common name black alpine sedge.
This sedge is native to western North America from Alaska to the Sierra Nevada in California, to Colorado, where it grows in wet areas in mountain, taiga, and tundra habitat.
Carex nigricans produces thick mats and loose clumps of stems up to 30 centimeters tall from a network of short rhizomes. The pistillate flowers have dark bracts and the fruit is covered in a dark colored, long beaked perigynium.