Perennials, 20-40+ cm; rhizomatous (rhizomes branched, horizontal to suberect). Stems 1 (sometimes from rosettes, rosettes sometimes clustered), tomentose. Basal leaves petiolate; blades broadly lanceolate to elliptic or spatulate, 20-40+ × 10-20+ mm, bases tapering, margins entire or subentire to dentate distally (faces tomentose). Cauline leaves abruptly reduced (petiolate or sessile; narrowly lanceolate to sublyrate, sharply toothed to pinnatisect or entire). Heads 6-12+ in corymbiform arrays (lateral cymiform arrays sometimes originating in leaf axils). Peduncles bracteate, densely lanate to sparsely tomentose. Calyculi inconspicuous. Phyllaries 13 or 21, green, 5-7 mm, densely tomentose (apices scarious). Ray florets 8-10(-13); corolla laminae 5-10 mm. Disc florets 25-35+; corolla tubes 3-4 mm, limbs 1.5-2 mm. Cypselae 1-1.5 mm, hirtellous on ribs; pappi 4-5 mm. 2n = 46.
Flowering late Apr-late May. Slopes on shale barrens; 300-800 m; Md., Pa., Va., W.Va.
Packera antennariifolia is known only from shale barrens or shale-derived soils in central Appalachia. Plants growing on steep slopes have stouter, more horizontal caudices and more extensive fibrous roots than specimens from other locations. Specimens from shale-derived soils, not growing directly on shale barrens, have weakly lobulate leaves and noticeably less hairiness.