Plants 20-105 cm; rhizomes short, thick, woody. Stems usually 1, erect, strigose in arrays. Leaves: basal and proximal cauline narrow-ing abruptly to elongated petioles, blades spatulate to lanceolate or ovate, 60-120(-150) × 14-45(-65) mm, gradually reduced distally, margins serrate (teeth 4-17), abaxial faces glabrous, glabrous or hairy along nerves, adaxial glabrous or sparsely strigose; mid to distal cauline petiolate to sessile, abruptly to gradually tapering to short broadly winged petiole-like bases, blades lanceolate, 22-46(-57) × 8-20(-29) mm, bases rounded, margins entire to slightly serrate, apices acute to acuminate, faces glabrous or sparsely hairy. Heads 2-110+ (1-10 per branch) in leafy, racemiform or short, axillary and terminal racemiform-paniculiform clusters, lateral branches erect, 4-43 cm. Peduncles 5-25 mm, densely short hispido-strigose; bracteoles 0-3, linear. Involucres campanulate, (8.6-)9.5-11.5(-12.5) mm. Phyllaries in 2-3 series, sometimes weakly unequal, glabrate, margins ciliate; outermost ovate, 3-5(-7) mm, acuminate, innermost lanceolate, 1-nerved, tapering to rounded tip. Ray florets 7-13; laminae (4-)4.5-6.5 × 1-2 mm. Disc florets 14-29; corollas (4.4-)5-6 mm; lobes 1-2 mm. Cypselae (± linear-obconic) 1.4-4.4 mm, glabrous; pappi (3.7-)5-6.5(-7.3) mm. 2n = 18. Flowering Aug-Sep. Sandy and gravelly soils, rocky ledges, and outcrops, open areas in woods and thickets; 0-1000+ m; St. Pierre and Miquelon; N.B., Nfld. and Labr. , N.S., Ont., P.E.I., Que.; Maine, N.H., N.Y., Vt. Solidago ×calcicola (Fernald) Fernald (S. virgaurea Linnaeus var. calcicola Fernald) is considered to be a hybrid between S. macrophylla and possibly a member of subsect. Triplinerviae.
Stems 1-10 dm from a branched caudex, glabrous or nearly so below the infl; lvs thin, ±hirsute on the midrib and main veins beneath and sometimes more shortly so above, ±basally disposed, but often only gradually reduced upwards, the larger ones with elliptic or ovate to subcordate, acuminate, sharply serrate blade 2-15 נ1-7 cm, abruptly contracted to the long petiole; infl narrow and elongate, conspicuously leafy-bracteate at least below; invol 8-11 mm, its bracts imbricate, acuminate or attenuate, thin and loose, often some with squarrose tip; rays 7-12, 5-8 mm; achenes glabrous, 4-5 mm; 2n=18, 54. Moist, cool, often shaded places; Catskill Mts., N.Y. and Mt. Greylock, Mass., to Nf., Lab., and Hudson Bay.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.