This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Slender; stem simple, glabrous, or minutely pubescent above, 2°-4° high. Leaves usually punctate, anise-scented when bruised, or sometimes inodorous, lanceolate, quite entire, acute or acuminate, 2'-4' long, 3"-8" wide, sessile, or the lowermost petioled; heads 2"-21/2" high, secund on the spreading racemes of the terminal, usually ample panicle; rays 3 or 4, 2"-3" long; bracts of the involucre oblong-lanceolate, acute, the inner much longer than the outer.
Solidago retrorsa Pursh, Fl. Am. Sept. 539. 1814.
Not Michx. 1803. S. tortifolia Ell. Bot. S. C. & Ga. 2: 377. 1824.
Stem slender, rough-pubescent or puberulent, 2°-3° high, simple. Leaves linear or linear-oblong, often twisted, scabrous, sessile, acute, 1'-2' long, 1 1/2"-3" wide, obscurely veined but with a distinct midrib, the lower serrate, the upper entire; heads about 2" high, secund on the usually recurved branches of the terminal panicle; rays 3-5, short; bracts of the involucre linear, obtuse or obtusish.
In dry sandy soil, Virginia to Florida and Texas, mostly near the coast. Autumn.
Stem rather stout, simple or branched above, 3°-7° high, hirsute. Leaves numerous, sessile, ovate-oblong, oblong-lanceolate, or sometimes lanceolate, thick, rough or hirsute on the margins and midrib beneath, the upper small, obtuse or obtusish, entire, the lower sparingly serrate, obtuse or acute, 1'-4' long with a broad base'; heads about 2" high, secund on the spreading or recurving branches of .the panicle; rays 7-10, small; bracts of the involucre, at least the outer, acute.
In moist pine-barrens, New Jersey to Florida and Louisiana. Aug.-Oct.
S. rugosa Mill. Gard. Dict. Ed. 8, No. 25. 1768. Solidago aspera Ait. Hort. Kew. 3: 212. 1789.
Stem hirsute or scabrous, rarely glabrate, usually stout, 1°-71/2° high, simple, or branched at the summit. Leaves more or less pubescent or scabrous, oval, oblong-lanceolate, or ovate-lanceolate, acute or acuminate, rarely obtusish at the apex, narrowed or obtuse at the base, rugosely veined on the lower surface, serrate, 1'-4' long, 4"-18" wide, sessile, or the lowest sometimes tapering into petioles; heads 1 1/2"-2" high, secund on the spreading or recurving, often leafy branches of the usually large and compound panicle; bracts of the involucre linear, obtuse or obtusish.
Usually in dry soil, in fields and along roadsides, Newfoundland to western Ontario, south to Florida and Texas. Consists of many races, differing in leaf-form, leaf-thickness and in pubescence. Supposed to hybridize with S. sempervirens L. Dyer's-weed. July-Nov.