Shrubs, 20-40 cm (deciduous; taproots woody). Stems erect (older portions gray, usually with shredding bark), branched, spinescent with age, glabrous or hirtellous. Leaves cauline; alternate (sometimes in axillary fascicles); petiolate or sessile; blades (gray-green) 1-nerved, narrowly lanceolate or narrowly obovate or spatulate, margins entire, faces glabrous, scabrous, or scabro-hirtellous, eglandular. Heads radiate or discoid, borne singly or in loose corymbiform arrays (pedunculate). Involucres campanulate to hemispheric or globose, (4-13 ×) 7-16 mm. Phyllaries 13-25 in 3 series, appressed (reflexing at maturity, bases yellowish, apices green), 1-nerved (flat), broadly ovate to elliptic-ovate, unequal, margins broadly hyaline, lacerate, faces glabrous. Receptacles flat to slightly convex, deeply pitted (pit margins ± lacerate), epaleate. Ray florets usually 5-14, sometimes 0, pistillate, fertile; corollas yellow. Disc florets 13-45, bisexual, fertile; corollas yellow, tubes longer than funnelform throats, lobes 5, reflexed, lanceolate; style-branch appendages triangular-lanceolate. Cypselae obconic, compressed, nervation not evident, faces densely sericeous to villous (some hairs ascending-spreading, others appressed and tortuous); pappi persistent, of 18-22, variably thick, broadly flattened, subequal, marginally barbellate or barbellulate to smooth, apically attenuate (ray) to spatulate (disc), setiform scales (heights equaling disc corollas) in 1-2 series, plus much shorter bristles or setae. x = 9. Acamptopappus is essentially endemic to the Mojave Desert of California, Arizona, Nevada, and Utah. The genus is recognized as low, white-barked, desert shrubs with pedunculate heads, borne singly or in loose, corymbiform arrays, with ovate phyllaries with broad hyaline margins, 0 or 5-14 yellow rays, sericeous to villous cypselae, and thick pappus scales.