Lowell E. Urbatsch, Loran C. Anderson, Roland P. Roberts, Kurt M. Neubig in Flora of North America (vol. 20)
Plants 20-50 cm. Stems erect to spreading, reddish tan, becoming darker, branched, short-stipitate-glandular, usually resinous. Leaves ascending to spreading; blades elliptic to narrowly oblanceolate (flat or somewhat concave adaxially), 10-35 × 2-5 mm, midnerves evident (often with 1-2 fainter, collateral veins), apices acute, apiculate, faces short-stipitate - glandular, usually gland-dotted; axillary fascicles absent. Heads in cymiform arrays (to 4 cm wide). Peduncles 1-10 mm (bracts 1-5, resembling phyllaries, stipitate-glandular). Involucres obconic, 5.5-7.5 × 2.5-4 mm. Phyllaries 30-40 in 4-5 series, tan, lanceolate to elliptic, 2-7 × 0.5-1.2 mm, strongly unequal, mostly chartaceous (bodies abruptly constricted at bases of appendages), midnerves faint, (margins membranous, sparsely ciliate apically), apices (usually recurved) usually acute to cuspidate, sometimes long-acuminate, abaxial faces glabrate, often gland-dotted. Ray florets 1-8; laminae elliptic, 3-4 × 0.8-1.3 mm. Disc florets 5-15; corollas 5-7 mm. Cypselae usually tan, sometimes reddish, narrowly obconic, 4-5.5 mm, glabrous or densely sericeous; pappi whitish tan, 4-5.5 mm. Flowering fall. Rock faces, cracks, and crevices and stony soils, usually on limestone; of conservation concern; ca. 2100 m; Ariz. Ericameria arizonica grows in the Grand Canyon.