Plants 30-120 cm; caudices branching, sometimes with elongate rhizomes forming new rosettes. Stems 1-10+ , erect, glabrous, sometimes sparsely hairy in arrays; usually with fascicles of small leaves in axils of distal leaves. Leaves: basal and proximal cauline tapering gradually to winged petioles, blades oblanceolate to ovate, 100-300 × 20-70 mm, usually multiple lateral nerves pronounced, margins sharply serrate, ciliate, faces glabrous; mid to distal cauline sessile, blades linear-lanceolate, 30-50 × 8-11 mm, reduced distally, margins entire or finely serrate. Heads 60-450 , secund, in paniculiform arrays, openly secund-pyramidal with proximal branches spreading-recurved, or as broad as long with proximal branches widely ascending, recurved (elm-tree shaped). Peduncles 1.5-6 mm, glabrous or sparsely strigillose; bracteoles 0-2, linear. Involucres narrowly campanulate, 3-4 mm. Phyllaries in 3-4 series, strongly unequal, outer ovate, acute, inner lanceolate, obtuse. Ray florets 7-12; laminae 2-2.5 × 0.2-0.5 mm. Disc florets 8-15; corollas 2.5-3 mm, lobes 0.5-0.8 mm. Cypselae 0.9-1.5 mm, sparsely strigose; pappi 2.5-3.5 mm. 2n = 18. Flowering Jul-Sep. Open sandy soils, disturbed areas, fields; 0-1000+ m; Man., N.B., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Del., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis. Several varieties of Solidago juncea have been described; they do not appear to warrant recognition, each grading into the other.