Encelia resinifera C.Clark
Family: Asteraceae
button brittlebush
[Encelia frutescens var. resinosa M.E. Jones ex Blake]
Encelia resinifera image
Curtis Clark  
Shrubs, 40-150 cm. Stems with slender branches from trunks, glabrate, developing fissured barks. Leaves cauline; petioles 2-6 mm; blades green, lanceolate to ovate, 10-25 mm, apices usually acute, sometimes obtuse, faces strigose, gland-dotted. Heads borne singly. Peduncles strigose to glabrate. Involucres 5-11 mm. Phyllaries lanceolate. Ray florets 8-13; corolla laminae 8-12 mm. Disc corollas yellow, 5-6 mm. Cypselae 5-8 mm; pappi 0. 2n = 36. Flowering May-Jul, Sep. Sandstone-derived soils; 1100-1700 m; Ariz., Utah. Plants of Encelia resinifera from the Grand Canyon of the Colorado with lengths of leaf blades and ray laminae at least three times their widths are subsp. tenuifolia.