Leptoloma cognatum Digitaria cognata is a species of grass known by the common names fall witchgrass,[2] Carolina crabgrass,[3] and mountain hairgrass.

The erect stems grow up to 56 centimeters tall.

The stem bases are tough and hairy.

[3] The inflorescence is a purple-tinged panicle with single-flowered spikelets.

[3] This grass provides graze for livestock and wild ungulates, and birds eat the seeds.