Dioecious. Plants (3-)10-15 cm. Stolons none. Basal leaves 1-nerved, linear to narrowly oblanceolate, 15-50 × 1-2(-4) mm, tips acute, not flagged, faces ± gray tomentose. Cauline leaves (gradually reduced distally) narrowly linear, 5-60 mm, distalmost flagged. Heads 2-8(-10) in subcapitate arrays. Involucres: staminate 4-5 mm; pistillate 4-6.5 mm. Phyllaries distally light brown, dingy brown, or olivaceous (apices acute-acuminate). Corollas: staminate 2.5-3.5 mm; pistillate 2.5-4 mm. Cypselae 1-1.8 mm, glandular-puberulent; pappi: staminate 3-4.5 mm (bristles barbellate at tips); pistillate 3-4.5 mm. 2n = 56.

Flowering in late spring-early summer. Dry, often sagebrush (Artemisia) covered hillsides and dry margins around seasonally moist depressions in sagebrush steppe of the Great Basin and Columbia Plateau; 1500-2300 m; Idaho, Nev., Oreg., Wash.

Antennaria stenophylla is a xerophyte in the Argenteae group. It is distinguished by relatively narrow leaves, heads in subcapitate clusters, and light brown, dingy brown, or olivaceous phyllary tips.