2. Arnoglossum atriplicifolium (Linnaeus) H. Robinson, Phytologia. 28: 294. 1974.
Cacalia atriplicifolia Linnaeus, Sp. Pl. 2: 835. 1753; C. paniculata Rafinesque; Conophora atriplicifolia (Linnaeus) Nieuwland; C. similis (Small) Nieuwland; Mesadenia atriplicifolia (Linnaeus) Rafinesque; M. pulverulenta Rafinesque; M. rotundifolia Rafinesque; M. similis Small; Senecio atriplicifolius (Linnaeus) Hooker
Plants 100–300 cm (rhizomatous). Stems smooth to weakly striate (glaucous). Basal leaves: blades usually ovate or ovate-cordate, to 21 cm (bases truncate or subcordate), margins shallowly lobed or dentate (sinuses smooth). Cauline leaves: (abaxial faces pale green, glaucous) proximal petiolate, ± deltate, margins coarsely dentate; distal petiolate or sessile, smaller. Involucres (7.5–)8–10(–10.5) mm. Phyllaries (pale green) oblong, midveins not winged (tips obtuse to acute, sparsely papillate). Corollas white, usually with green, sometimes purple, 8–9.5(–13) mm. Cypselae fusiform or ellipsoid, 4–5 mm (brown or purplish, 8–10-ribbed); pappi 5–6(–7) mm (readily falling). 2n = 50, 52, 56.
Flowering Jul–Nov. Edges of woods, pastures, roadsides; 10–600 m; Ala., Ark., Del., Fla., Ga., Ill., Ind., Kans., Ky., Md., Mich., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Va., W.Va., Wis.