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..
Stem simple, rather stout, glabrous, or sparingly pubescent above, 2°-4° high. Leaves thin, pinnately veined, the lower and basal ones broadly ovate or oval, short-acuminate, 3'-16' long, 1'-5' wide, narrowed into margined petioles, or subcordate, sharply and coarsely serrate; upper leaves sessile, ovate to oblong, acute or acuminate, more or less serrate, smaller; heads 2 1/2-3" high, secund on the lateral racemose branches of the terminal, often leafy panicle; rays 5-7, large; bracts of the involucre oblong, obtuse; achenes glabrous or nearly so.
In rich woods, Maine to Ontario, Virginia and Tennessee. Ascends to 2700 ft. in the Adiron-dacks. July-Oct.
Stem slender, glabrous, or pubescent above, 1°-5° high. Leaves thin, triple-nerved, linear-lanceolate, 2'-s' long, 3"-5" wide, entire, or serrate with somewhat appressed teeth, acuminate at the apex, narrowed at the base, sessile, or the lowest petioled, glabrous, or pubescent; heads small, 1 1/4" high or less, secund on the spreading branches of the often large panicle; rays 4 - 6, short; bracts of the involucre thin, linear, acutish; achenes small, nearly glabrous.
Hillsides, thickets and banks of streams, Newfoundland to Virginia, Ontario, Saskatchewan, Tennessee and South Dakota. Aug.-Oct.
Solidago gilvocanescens Rydb. differs in being canescent; it ranges from Illinois to Manitoba, Saskatchewan, Nebraska and Utah.
Solidago serotina Ait. Hort. Kew. 3: 211. 1789.
S. gigantea Ait. Hort. Kew. 3: 211. 1789.
Stem stout, 3°-8° high, glabrous, sometimes glaucous. Leaves lanceolate or oblong-lanceolate, thin, triple-nerved, sharply serrate, or nearly entire, sessile, or the lowest petioled, glabrous on both sides or pubescent beneath, more or less rough-margined, 3'-6' long, 2"-15" wide, acuminate at the apex, narrowed at the base; heads 21/2"-3" high, crowded on the spreading or recurving branches of the usually large and often leafy panicle, which are sometimes puberulent; bracts of the involucre oblong, thin, obtuse; rays 7-15, rather large; achenes finely pubescent.
In moist soil, New Brunswick to British Columbia and Oregon, south to Georgia, Texas and Utah. Ascends to 2300 ft. in Virginia. Aug.-Oct.