[Encelia argophylla (D. C. Eat.) A. Gray, moreEnceliopsis argophylla var. argophylla , Helianthella argophylla (D. C. Eaton) A. Gray, Tithonia argophylla D.C. Eat.]
Perennials, 15-80 cm; herbage silvery, hairs fine, ± appressed. Leaves: petioles winged, wings merging with blades; blades rhombic or widely elliptic, 4-10 × 2-8 cm. Peduncles 30-80 cm. Involucres 15-25 mm. Phyllaries in 4-6 series, lanceolate to ovate, apices acuminate. Ray florets 20-35; corollas deep yellow, laminae 12-30 mm (1-1.2 times disc diams.). Cypselae 9-13 × 4-5 mm, hirsute; pappi usually of 2 awns 1-2 mm (plus minute scales or teeth), sometimes 0.
Flowering Apr-May. Stony plains, hillsides; 1000-1500 m; Ariz., Nev.