Plants 10-50(-120+) cm (annuals, internodes not winged). Leaves all or mostly alternate (proximal usually opposite); blades deltate-ovate or rhombic to lanceolate, 3-8(-12+) × 2-4(-6+) cm, bases broadly cuneate to ± truncate, margins coarsely toothed to subentire, apices acute to attenuate, faces strigoso-scabrellous to sericeous. Heads usually borne singly, sometimes 2-3+ in loose, cymiform or corymbiform arrays. Involucres ± hemispheric to saucerlike, 10-20+ mm diam. Phyllaries 12-18+ in 1-2 series, ± erect to spreading, lance-ovate or lance-linear to linear, 6-8+ mm. Ray florets (8-)12-15+; laminae 8-10(-20+) mm. Disc florets 80-150+; corollas yellow. Cypselae dark brown to blackish, narrowly obovate, 3.5-5+ mm, faces ± strigillose; pappi 0.5-1(-2) mm (0 on ray cypselae). 2n = 34. Flowering Aug-Oct. Swales, disturbed sites; 10-2500 m; Ala., Ariz., Ark., Calif., Colo., Fla., Ga., Ill., Iowa, Kans., La., Mo., Mont., Nebr., Nev., N.Mex., N.Y., N.C., Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Wyo.; Mexico; West Indies; South America; introduced in Asia, Pacific Islands (Hawaii), Australia. Native distribution of Verbesina encelioides in the flora area is uncertain. Plants of Verbesina encelioides from ca. 100°W (e.g., c Texas) and eastward usually have auriculate petiole bases and have been called var. encelioides; plants from the west usually lack auricles and have been called var. exauriculata.
Erect annual 2-10 dm, the stem and lower lf-surfaces strigose-canescent, the upper lf-surfaces sometimes greener but still strigose; lvs alternate (except the lower), ovate or deltoid, sometimes rather narrowly so, rather coarsely toothed, especially near the base, 4-13 נ2-10 cm; petiole well developed, commonly auriculate-dilated at base; heads long-pedunculate in an open infl, the disk 13-20 mm wide infl; invol bracts loose or a little spreading, scarcely imbricate, canescently strigose or hirsute; rays 10-15, pistillate, yellow, evidently trilobed, 1-1.5 cm; achenes winged, a little spreading but not reflexed, the fruiting head hemispheric; 2n=34. Open, often waste places; native of Mex. and sw. U.S., casually intr. with us, especially westward. May-Oct. (Ximenesia e.; X. exauriculata) Ours is var. encelioides.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.