Subshrubs or shrubs, 50-150 cm. Stems with slender branches from trunks, glabrous, developing fissured barks. Leaves cauline; petioles 2-7 mm; blades green, elliptic or narrowly ovate, 10-25 mm, apices obtuse, faces strigose. Heads borne singly. Peduncles strigose. Involucres 6-12 mm. Phyllaries lanceolate. Ray florets 0. Disc corollas yellow, 5-6 mm. Cypselae 6-9 mm; pappi 0 or of 2 bristlelike awns. 2n = 36. Flowering Feb-May, Aug-Sep. Desert washes, flats, slopes, roadsides; 0-800 m; Ariz., Calif., Nev.; Mexico (Baja California, Sonora). Plants of Encelia frutescens in the flora area are var. frutescens; var. glandulosa C. Clark, with glandular, strigose leaves, is found in northeastern Baja California and is not expected here.
Wiggins 1964, FNA 2006, Benson and Darrow
Common Name: button brittlebush Duration: Perennial Nativity: Native Lifeform: Shrub General: Much branched, low, usually rounded shrub 50-150 cm tall with slender branches, glabrous with developing fissured bark; stems whitish. Leaves: Cauline, on petioles 2-7 mm; blades elliptic to oblong, 10-25 mm, obtuse to acute at apex, broadly cuneate to truncate at base, faces strigose, entire margins; dark green. Flowers: Heads borne singly on strigose peduncles; involucres 6-12 mm, bracts imbricate and unequal, lanceolate phyllaries; rays mostly lacking; disk flowers 5-6 mm, yellow, short tube glandular-puberulent. Fruits: Black cypselae 6-9 mm, white villous along margins with silky hairs along middle of each face; pappus none or with 1-2 weak bristlelike awns. Ecology: Found on stony slopes, along washes, on slopes and roadsides from sea level to 4,000 ft (1219 m); flowers March-October. Notes: Notably different from Encelia farinosa by virtue of the bright green leaves sometimes densely pubescent, rather than the gray farinose leaves in E. farinosa. Often flower heads are much smaller as well. Note that the flower heads may or may not have rays florets. Ethnobotany: Used as a seasoning and as a remedy for shingles. Etymology: Encelia is named for Christoph Entzelt (1517-1583) a German naturalist, while frutescens means shrubby. Synonyms: Encelia frutescens var. frutescens, Simsia frutescens Editor: SBuckley, 2010