Culms cespitose, straight, 10--30 cm, stiff. Leaves: basal leaves (with several outer dead ones usually present), to 9 cm x 3 mm, apex callous, sparingly pilose; cauline leaves to 5 cm x 2 mm. Inflorescences: glomerules 1(--3); peduncles, not exceeding 5 mm; proximal inflorescence bract conspicuous, leaflike, usually conspicuously exceeding inflorescence; bracts mostly inconspicuous; bracteoles clear or light to dark brown, occasionally to 1/2 tepal length. Flowers: tepals with broad clear margins and apex (apex acute-acuminate), 1.9--2.5 mm, apex acute-acuminate; outer whorl ± equaling to exceeding inner whorl; anthers ± equaling filaments. Capsules dark reddish, shining, ovoid, generally shorter than tepals. Seeds translucent, brown, ellipsoid, 0.9--1.1 mm; caruncle barely visible. 2n = 24.

Flowering and fruiting summer. Sandy sea shores with herbaceous vegetation to turfy tundra, often by water, to alpine flats; 0--400 m; Greenland; B.C., Man., Nfld. and Labr. (Labr.), N.W.T., Nunavut, Que., Yukon; Alaska.

The culms of Luzula groenlandica are straight and stiff; basal leaves are sparingly pilose.