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..
Solidago patula Muhl.; Willd. Sp. Pl. 3: 2059 1804.
Stem stout, rather rigid, usually simple, glabrous, or sometimes puberulent above, 2°-7° high. Leaves thick, glabrous beneath, exceedingly rough above, pinnately veined, the lower and basal ones very large, 3'-16' long, 1 1/2'-5' wide, oval or elliptic, narrowed into margined petioles, the upper smaller, oval or oblong, sessile, acute, finely serrate or the uppermost entire; heads 2"-3 1/2 " high, secund on the widely spreading and recurving branches of the loose panicle; rays small; bracts of the involucre linear-oblong, obtuse.
In swamps, Maine and Ontario to Minnesota, south to Georgia, Missouri and Texas. Ascends to 5000 ft. in North Carolina. Stem strongly angled, at least below. Aug.-Oct.
Solidago ulmifolia Muhl.; Willd. Sp. Pl. 3: 2060. 1804.
Stem slender, glabrous, or puberulent at the summit, 2°-4° high, simple, or branched above, the arched branches puberulent or pubescent. Leaves thin, oblong to elliptic-lanceolate, acute or acuminate at the apex and base, coarsely and sharply serrate, pinnately veined, glabrous or sparingly pubes cent, the lower and basal ones wider, 3'-5' long, 1'-1 1/2' wide, narrowed into margined petioles, the upper smaller, sessile; heads 2"-3" high, secund on the usually few and elongated, usually leafy branches of the panicle; rays few, small, deep yellow; bracts of the involucre oblong-lanceolate, obtusish.
In woods and copses, Nova Scotia to Georgia, west to Minnesota, Missouri and Texas. Ascends to 2100 ft. in Virginia. July-Sept.
Solidago microphylla Engelm., ranging from Kansas to Texas, appears to be a race of this species with acutish inner bracts of the involucre.
S. Boottii Hook. Comp. Bot. Mag. 1: 97. 1835.
Stem glabrous, or puberulent above, slender, usually branched near the summit, 2°-5° high. Leaves firm, pinnately and finely reticulate-veined, the lower and basal ones ovate or oblong-lanceolate, narrowed into margined, sometimes ciliate petioles, acuminate at the apex, sharply and rather coarsely serrate, 3'-6' long, the upper smaller, entire, or finely serrate, sessile; heads 2"-3" high, secund on the elongated, spreading or recurving branches of the usually ample panicle; rays few, small; bracts of the involucre linear-oblong, obtuse; achenes pubescent.
In dry woods, Virginia to Florida and Texas. Recorded from Missouri. Ascends to 3000 ft. in Virginia. July-Sept.