Leaf faces glabrous or hirtellous. Heads in loose, corymbiform arrays. Involucres hemispheric to globose, 7-10 mm wide. Rays 0. The two varieties were mapped as geographically intermingling in southern California (M. A. Lane 1988). Considerable variation in expression of vestiture occurs in the area where the hirtellous-leaved plants grow and identifications should be recognized as arbitrary.
FNA 2003, Jepson 2012, Kearney and Peebles 1969
Duration: Perennial Nativity: Native Lifeform: Subshrub General: Perennial herbs, 20-40 cm tall, from a woody taproot; stems branching, ascending to erect, younger portions with white bark, older portions gray, spinescent, and usually with shredding bark; herbage glabrous to hirtellous. Leaves: Alternate, sometimes in axillary fascicles, petiolate or sessile; blades to 1.5 cm long and to 3 mm wide, generally linear to oblanceolate, or spatulate (spoon-shaped), spreading-ascending to appressed-erect, 1-nerved; margins entire to minutely spine-tipped, faces glabrous, eglandular, scabrous, or hirtellous- pale green to gray green. Flowers: Flower heads yellow, showy, discoid, arranged in loose, rounded to flat-topped clusters; involucre (ring of bracts wrapped around the flower head) hemispheric to spheric, 8-16 mm diameter, the bracts (phyllaries) 13-25 in 3 series, broadly ovate, dry, blunt, with a greenish subapical spot, yellowish bases, and scarious margins; disc florets 13-45, the corollas yellow. Fruits: Achenes (cypselae) obconic to turbinate, compressed, densely villous with long white, bronze, or brown hairs; topped with a pappus of numerous narrowly linear paleae, plus much shorter bristles. Ecology: Found on gravelly or rocky soils, in grasslands, deserts, and woodlands, below 6,500 ft (1981 m); flowers March-October. Distribution: AZ, CA, NV, UT Notes: The genus Acamptopappus is essentially endemic to the Mojave Desert of California, Arizona, Nevada, and Utah, characterized 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 achenes, and thick pappus scales. A. sphaerocephalus has yellow flower heads that lack ray florets. There are two varieties: A. s. var. sphaerocephalus has glabrous leaf surfaces with hirtellous margins, and A. s. var. hirtellus has leaves with hirtellous faces and margins. However, as FNA notes, there is considerable variation in the Ethnobotany: Mashed plant used as a salve for pain. Synonyms: Haplopappus sphaerocephalus Editor: LCrumbacher2012, AHazelton 2015 Etymology: Acamptopappus comes from the Greek akamptos, "stiff," and pappos, "pappus," thus meaning stiff or unbending pappus, while sphaerocephalus is from the Greek meaning "sphere- or round-headed".