Dioecious. Plants 5-15(-20) cm (stems woolly). Stolons 4-10 cm (arched). Basal leaves 1-3-nerved, narrowly to broadly spatulate, or narrowly rhombic-obovate, 20-45 × 3-15 mm, tips mucronate, faces densely white. woolly. Cauline leaves linear, (2-)5-40 mm, not flagged. Heads (4-)7-25, in racem-iform to paniculiform or corymbiform arrays. Involucres: staminate 3-5 mm; pistillate 4.5-6(-7) mm. Phyllaries distally whitish (mostly staminate) or grayish stramineous to light brown. Corollas: staminate 2.5-4 mm; pistillate 3.5-5 mm. Cypselae 1-1.8 mm, glabrous; pappi: staminate 3-4.5 mm; pistillate 4-6 mm. 2n = 28.

Flowering summer. Moist alkaline basins in sagebrush steppe; 1500-2300 m; Idaho, Nev., Wyo.

Antennaria arcuata is known from three widely disjunct areas in Blaine County, Idaho; Elko County, Nevada; and Fremont County, Wyoming (R. J. Bayer 1992). It is characterized by arching stolons and white-woolly indument (Bayer) and is not easily confused with other species of Antennaria.