Dioecious. Plants 7-16 cm (bases somewhat woody). Stolons 7-16 cm (usually erect, slightly woody). Basal leaves 1-nerved, narrowly spatulate to cuneate, 10-17 × 2-5.4 mm, tips mucronate, faces gray-tomentose. Cauline leaves linear, 8-18 mm, not flagged (apices acute). Heads 3-8 in corymbiform arrays. Involucres: staminate 3-6 mm; pistillate 4-6.5 mm. Phyllaries distally whitish, yellowish, or pale brownish (often streaked with pink or rose). Corollas: staminate 2.5-3.5 mm; pistillate 2.5-3.5 mm. Cypselae 0.5-1.2 mm, glabrous; pappi: staminate 3-4.5 mm; pistillate 3-5 mm. 2n = 28, 56.

Flowering summer. Sagebrush steppe to open, dry, coniferous montane forests to subalpine meadows; 1100-3400 m; Alta., B.C., Sask.; Ariz., Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.

Antennaria umbrinella is a primary sexual progenitor of the A. rosea complex (R. J. Bayer 1990b). It is characterized by somewhat erect, slightly woody stolons and phyllaries that are usually various shades of brown, sometimes white, or streaked with pink or rose (Bayer 1987b).