Plants 20-70(-100) cm; caudices thick, woody. Stems single (sometimes purplish brown, ridged), glabrous, strigose distally in arrays. Leaves: basal and proximal tapering to winged petioles, blades (basal) spatulate, 20-40 mm, (proximal) obovate to oblanceolate or elliptic, 60-150(-200) × 30-55 mm, margins serrate (teeth shallow to 5 mm), ciliate, acute to obtuse, acuminate or mucronate, faces abaxially glabrate to sparsely strigose, especially on nerves, adaxially glabrous; mid and distal cauline sessile, lancelate or oblanceolate to elliptic, 30-100 × 20-40 mm, reduced distally, margins serrate to entire distally. Heads 20-180+ (1-6 per branch), in leafy wand-paniculiform arrays (2-)10-20(-40) cm, lateral branches usually not exceeding subtending leaf bracts. Peduncles 1-3 mm, strigose; bracts and bracteoles lanceolate to ovate, grading into phyllaries. Involucres campanulate, ca. 5 mm. Phyllaries in 3-4 series, appressed, strongly unequal, outer grading from ovate bracteoles, mid oblong, rounded, inner linear-oblong, acute, glabrous. Ray florets ca. 6-10; laminae 1.5-2.5 × 0.5 mm. Disc florets ca. 10; corollas 3.5-5 mm, lobes 1-1.5 mm. Cypselae (narrowly obconic) 2.5-3 mm, moderately strigillose; pappi ca. 4 mm (sometimes weakly clavate). 2n = 36. Flowering Aug-Sep. Sandstone and limestone bluffs and ledges along Mississippi River; 200-400 m; Ill., Iowa, Minn., Wis. Solidago sciaphila is similar to S. speciosa, but the proximal leaves are obviously serrate.
Plants 4-11 dm from a branched caudex, glabrous except for a little puberulence in the infl; lvs basally disposed, the larger ones with broadly oblanceolate to obovate or elliptic blade to 15 נ8 cm, crenate, serrate, or rarely subentire, tapering to the petiole; middle and cauline lvs progressively reduced, becoming sessile or subsessile and ±rhombic, toothed or sometimes entire; infl an elongate, bracteate, terminal thyrse, rarely branched; invol 5-7 mm, its bracts strongly imbricate, glabrous, obtuse; rays 7-8, 2.5-4 mm; achenes short-hairy. Calcareous or sandy cliffs; sw. Wis. and adj. Ill., Minn., and Io.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.